Author: "Christophe Gatel" / Publication Year Range: Last 10 years - Searchworks@Jio Institute Digital Library Search Results

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71 results on '"Christophe Gatel"'

1. Stochastic hexagonal injectors in artificial spin ice

Author: Robert Puttock, Anaïs Fondet, Ingrid M. Andersen, Mark C. Rosamond, Alexander Fernández Scarioni, Hans W. Schumacher, Etienne Snoeck, Christophe Gatel, and Olga Kazakova
Subjects: Materials of engineering and construction. Mechanics of materials, TA401-492
Abstract: Abstract Artificial spin ice (ASI) systems have emerged as powerful platforms for exploring the fundamental aspects of magnetic frustration and topological phenomena in condensed matter physics. In this study, we investigate the bountiful effects that result from introducing hexagonal magnetic defects into an ASI lattice. The stochastic stabilisation of a plethora of metastable states in the hexagonal defects are explored, as well as harnessing the defect magnetisation state for the selective injection of emergent monopoles of different polarities and proximities within the lattice. We demonstrate a mechanism for tailoring the ASI behaviour using the magnetic state of the defect, which is of interest to applications including magnetic memory devices and spin-based logic.
Published: 2024
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2. Defect-induced monopole injection and manipulation in artificial spin ice

Author: Robert Puttock, Ingrid M. Andersen, Christophe Gatel, Bumsu Park, Mark C. Rosamond, Etienne Snoeck, and Olga Kazakova
Subjects: Science
Abstract: Artificial spin ice systems offer a promising platform to study the motion of emergent magnetic monopoles, but controlled nucleation of monopoles is challenging. Here the authors demonstrate controlled injection and propagation of emergent monopoles in an artificial spin ice utilizing ferromagnetic defects.
Published: 2022
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3. Optimized Route for the Fabrication of MnAlC Permanent Magnets by Arc Melting

Author: Hugo Martínez-Sánchez, Juan David Gámez, José Luis Valenzuela, Hernan Dario Colorado, Lorena Marín, Luis Alfredo Rodríguez, Etienne Snoeck, Christophe Gatel, Ligia Edith Zamora, Germán Antonio Pérez Alcázar, and Jesús Anselmo Tabares
Subjects: rare-earth-free permanent magnets, electric arc melting, τ-MnAlC, ε-MnAlC, Organic chemistry, QD241-441
Abstract: The rare-earth-free MnAlC alloy is currently considered a very promising candidate for permanent magnet applications due to its high anisotropy field and relatively high saturation magnetization and Curie temperature, besides being a low-cost material. In this work, we presented a simple fabrication route that allows for obtaining a magnetically enhanced bulk τ-MnAlC magnet. In the fabrication process, an electric arc-melting method was carried out to melt ingots of MnAlC alloys. A two-step solution treatment at 1200 °C and 1100 °C allowed us to synthesize a pure room-temperature ε-MnAlC ingot that completely transformed into τ-MnAlC alloy, free of secondary phases, after an annealing treatment at 550 °C for 30 min. The Rietveld refinements and magnetization measurements demonstrated that the quenched process produces a phase-segregated ε-MnAlC alloy that is formed by two types of ε-phases due to local fluctuation of the Mn. Room-temperature hysteresis loops showed that our improved τ-MnAlC alloy exhibited a remanent magnetization of 42 Am2/kg, a coercive field of 0.2 T and a maximum energy product, (BH)max, of 6.07 kJ/m3, which is higher than those reported in previous works using a similar preparation route. Experimental evidence demonstrated that the synthesis of a pure room-temperature ε-MnAlC played an important role in the suppression of undesirable phases that deteriorate the permanent magnet properties of the τ-MnAlC. Finally, magnetic images recorded by Lorentz microscopy allowed us to observe the microstructure and magnetic domain walls of the optimized τ-MnAlC. The presence of magnetic contrasts in all the observed grains allowed us to confirm the high-quality ferromagnetic behavior of the system.
Published: 2022
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4. Synthesis of magnetic Fe and Co nano-whiskers and platelets via physical vapor deposition

Author: Wenting Huang, Christophe Gatel, Zi-An Li, and Gunther Richter
Subjects: Magnetic nanowires, Single domain, Magnetic vortex, Electron holography, Materials of engineering and construction. Mechanics of materials, TA401-492
Abstract: Fe and Co nano-whiskers and Co platelets were synthesized via physical vapor deposition without any template and catalyst. Transmission electron microscopic analyses revealed that the Fe whiskers were all single crystal with whisker axis along [1 0 0] crystallographic direction. Both FCC and HCP crystal structures were found in the Co whiskers with stacking faults and micro-twins. Off-axis Electron holography results showed that all the whiskers synthesized were magnetic single domain structures. Vortex state was observed in a small platelet of high symmetry.
Published: 2021
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5. Coupling Electronic Holography and Finite-Element Method Simulations to Measure Electric Fields in Nanocapacitors

Author: Kilian Gruel, Raphaël Serra, Leifeng Zhang, Aurélien Masseboeuf, Martin J Hÿtch, and Christophe Gatel
Subjects: Instrumentation
Published: 2022

6. Dynamic automation in transmission electron microscopy: application to electron holography

Author: Julien Dupuy, Christophe Gatel, and Martin Hÿtch
Subjects: Materials science, business.industry, Transmission electron microscopy, Optoelectronics, business, Instrumentation, Automation, Electron holography
Published: 2021

7. Ferromagnetic Ni Nanoparticle with Controlled Anisotropy: From Polyhedral to Planar Tetrapods

Author: Georgiana Maties, Marion Luu, Kosseila Ait-Oukaci, Ilona Lecerf, Cécile Marcelot, Anaïs Fondet, Simon Cayez, Christophe Gatel, Thomas Blon, Bruno Chaudret, Lise-Marie Lacroix, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Fédération de recherche « Matière et interactions » (FeRMI), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Optoélectronique Quantique (LPCNO), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), ANR-17-EURE-0009,NanoX,Science et Ingénierie à l'Echelle Nano(2017), ANR-19-CE09-0021,POMADE,Aimants intégrés submillimétriques pour dispositifs portables(2019), and ANR-17-CE24-0047,IODA,Microscopie électronique in operando pour l'analyse de composants(2017)
Subjects: organometallic chemistry, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, General Energy, electron holography, nanoparticle, nanomagnetism, [CHIM.MATE]Chemical Sciences/Material chemistry, Physical and Theoretical Chemistry, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials
Abstract: International audience; Liquid phase syntheses mainly yield nanoparticles with compact shapes, such as spheres or cubes. However, controlling not only the size but also the shape of magnetic nanoparticles would enable a fine tuning of their intrinsic properties, due to the shape anisotropy induced by long-range dipolar interactions. We report here a fairly simple approach based on the reduction of an amidinate complex in presence of a mixture of long chains acid and amine to yield ferromagnetic Ni nanoparticles. The formation of stable Ni complexes could be promoted in situ by increasing the acid concentration, thus allowing to tune the final particle size. While amine could be use as soft reducing agent, dihydrogen was essential to promote anisotropic shapes. Electron holography combined with micromagnetic simulations showed that the resulting shape anisotropy could impose complex magnetic configurations within planar tetrapods. Regarding the heating efficiency, which directly scales with the magnetic hysteresis loop area, maxima of 100W.g-1 were found for nanoplates and nanorods, opening promising perspectives for magnetically-induced catalysis.
Published: 2022

8. Key Signatures of Magnetofossils Elucidated by Mutant Magnetotactic Bacteria and Micromagnetic Calculations

Author: Matthieu Amor, Juan Wan, Ramon Egli, Julie Carlut, Christophe Gatel, Ingrid Marie Andersen, Etienne Snoeck, Arash Komeili, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées (INSA)-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Department of Plant and Microbial Biology [Berkeley], University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Zentralanstalt für Meteorologie und Geodynamik [Vienna] (ZAMG), Institut de Physique du Globe de Paris (IPG Paris), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT), Department of Molecular and Cell Biology, ANR-10-EQPX-0038,MIMETIS,Microscopie Interférométrique et Microscopie Electronique en Transmission In Situ(2010), and European Project: 823717,ESTEEM3
Subjects: Geophysics, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Geochemistry and Petrology, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], Earth and Planetary Sciences (miscellaneous), [CHIM.CRIS]Chemical Sciences/Cristallography, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], ComputingMilieux_MISCELLANEOUS
Abstract: International audience; Magnetotactic bacteria (MTB) produce single-stranded or multi-stranded chains of magnetic nanoparticles that contribute to the magnetization of sediments and rocks. Their magnetic fingerprint can be detected in ancient geological samples and serve as a unique biosignature of microbial life. However, some fossilized assemblages bear contradictory signatures pointing to magnetic components that have distinct origin(s). Here, using micromagnetic simulations and mutant MTB producing looped magnetosome chains, we demonstrate that the observed magnetofossil fingerprints are produced by a mixture of single-stranded and multi-stranded chains, and that diagenetically induced chain collapse, if occurring, must preserve the strong uniaxial anisotropy of native chains. This anisotropy is the key factor for distinguishing magnetofossils from other populations of natural magnetite particles, including those with similar individual crystal characteristics. Furthermore, the detailed properties of magnetofossil signatures depend on the proportion of equant and elongated magnetosomes, as well as on the relative abundances of single-stranded and multi-stranded chains. This work has important paleoclimatic, paleontological, and phylogenetic implications, as it provides reference data to differentiate distinct MTB lineages according to their chain and magnetosome morphologies, which will enable the tracking of the evolution of some of the most ancient biomineralizing organisms in a time-resolved manner. It also enables a more accurate discrimination of different sources of magnetite particles, which is pivotal for gaining better environmental and relative paleointensity reconstructions from sedimentary records.
Published: 2022

9. Mapping electric fields in real nanodevices by operando electron holography

Author: Maria Brodovoi, Kilian Gruel, Aurélien Masseboeuf, Lucas Chapuis, Martin Hÿtch, Frédéric Lorut, Christophe Gatel, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), STMicroelectronics [Crolles] (ST-CROLLES), SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), and ANR-17-CE24-0047,IODA,Microscopie électronique in operando pour l'analyse de composants(2017)
Subjects: Physics and Astronomy (miscellaneous), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics
Abstract: International audience; Nanoelectronic devices play an essential role in many domains, and their development and improvement attract considerable attention in fundamental and applied research. Access to the local physical processes involved in these nanosystems during their operation is, therefore, crucial. We show how electric fields in real nanodevices can be studied under working conditions using operando electron holography. A specific sample preparation method was first developed to bias electron-transparent nanodevices extracted from production lines while ensuring their electrical connectivity and functionality without employing dedicated probe-based holders. Metal–insulator–metal nanocapacitors were prepared using this approach based on focused ion beam circuit modification. Operando electron holography allowed the electric potential to be quantitatively mapped in the active areas, and between devices, while biasing the devices in situ. Experimental results were compared with finite element method modeling simulations to determine local electrical parameters. We demonstrate that electrical properties, such as capacitance and surface charge density, can be measured at the nanoscale and have been preserved by our sample preparation methodology when compared to macroscopic measurements. This work paves the way for mapping the local electrical properties of more complex biased devices.
Published: 2022

10. In-Situ Electrical Biasing of Electrically Connected TEM Lamellae with Embedded Nanodevices

Author: Cécile Marcelot, F. Lorut, Christophe Gatel, Martin Hÿtch, Lucas Chapuis, Kilian Gruel, Maria Brodovoi, Aurélien Masseboeuf, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), STMicroelectronics [Crolles] (ST-CROLLES), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), French National Research Agency under the 'Investissement d'Avenir' program reference No. ANR-10-EQPX-38-01French national project IODA (ANR-17-CE24-0047), European Project: 823717,ESTEEM3, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: In situ, Materials science, business.industry, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, Biasing, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], business
Abstract: International audience; In response to a continually rising demand for high performance and low-cost devices, and equally driven by competitivity, the microelectronics industry excels in meeting innovation challenges and further miniaturizing products. However, device shrinkage and the increasing complexity of device architecture require local quantitative studies. In this paper, we demonstrate with a case study on a nanocapacitor, the capability of transmission electron microscopy in electron holography mode to be a unique in-situ technique for mapping electric fields and charge distributions on a single device.
Published: 2021

11. Field tunable three-dimensional magnetic nanotextures in cobalt-nickel nanowires

Author: Cristina Bran, Tore Niermann, Ingrid Marie Andersen, D. Oliveros, Axel Lubk, Daniel Wolf, Manuel Vázquez, Luis A. Rodríguez, Ulrich K. Rößler, Etienne Snoeck, Christophe Gatel, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Leibniz Institute for Solid State and Materials Research (IFW Dresden), Leibniz Association, Departamento de Física–Universidad del Valle, universidad de valle, Sor Juana Ines de la Cruz, Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institut fur Optik und Atomare Physik, Technical University of Berlin / Technische Universität Berlin (TU), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)
Subjects: Materials science, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Magnetization, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), 0103 physical sciences, [CHIM.CRIS]Chemical Sciences/Cristallography, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Anisotropy, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Condensed Matter - Materials Science, Anisotropy energy, Spintronics, Condensed matter physics, Condensed Matter - Mesoscale and Nanoscale Physics, Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, Magnetocrystalline anisotropy, 3. Good health, Vortex, Magnetic field, Domain wall (magnetism), [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology
Abstract: Cylindrical magnetic nanowires with large transversal magnetocrystalline anisotropy have been shown to sustain non-trivial magnetic configurations resulting from the interplay of spatial confinement, exchange, and anisotropies. Exploiting these peculiar 3D spin configurations and their solitonic inhomogeneities are prospected to improve magnetization switching in future spintronics, such as power-saving magnetic memory and logic applications. Here we employ holographic vector field electron tomography to reconstruct the remanent magnetic states in CoNi nanowires with 10 nm resolution in 3D, with a particular focus on domain walls between remanent states and ubiquitous real-structure effects stemming from irregular morphology and anisotropy variations. By tuning the applied magnetic field direction, both longitudinal and transverse multi-vortex states of different chiralities and peculiar 3D features such as shifted vortex cores are stabilized. The chiral domain wall between the longitudinal vortices of opposite chiralities exhibits a complex 3D shape characterized by a push out of the central vortex line and a gain in exchange and anisotropy energy. A similar complex 3D texture, including bent vortex lines, forms at the domain boundary between transverse-vortex states and longitudinal configurations. Micromagnetic simulations allow an understanding of the origin of the observed complex magnetic states., 22 pages, 5 figures, preprent of original paper
Published: 2021

12. Magnetic imaging using geometrically constrained nano-domain walls

Author: David Cox, Olga Kazakova, Matteo Pancaldi, Paolo Vavassori, Héctor Corte-León, Christophe Gatel, Etienne Snoeck, Luis A. Rodríguez, Vladimir Antonov, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Department of Mathematics and Computer Science, Amherst College, Department of Physics [Egham], Royal Holloway [University of London] (RHUL), National Physical Laboratory [Teddington] (NPL), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Nanostructure, Magnetic moment, Magnetic domain, Condensed matter physics, Demagnetizing field, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Electron holography, 0104 chemical sciences, Magnetization, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], [CHIM.CRIS]Chemical Sciences/Cristallography, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Materials Science, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Magnetic force microscope, 0210 nano-technology, Anisotropy, ComputingMilieux_MISCELLANEOUS
Abstract: Magnetic nanostructures, as part of hybrid CMOS technology, have the potential to overcome silicon's scaling limit. However, a major problem is how to characterize their magnetization without disturbing it. Magnetic force microscopy (MFM) offers a convenient way of studying magnetization, but spatial resolution and sensitivity are usually boosted at the cost of increasing probe-sample interaction. By using a single magnetic domain wall (DW), confined in a V-shape nanostructure fabricated at the probe apex, it is demonstrated here that the spatial resolution and the magnetic sensitivity can be decoupled and both enhanced. Indeed, owing to the nanostructure's strong shape anisotropy, DW-probes have 2 high and 2 low magnetic moment states with opposite polarities, characterised by a geometrically constrained pinned DW, and curled magnetization, respectively. Electron holography studies, supported by numerical simulations, and in situ MFM show that the DW-probe state can be controlled, and thus used as a switchable tool with a low/high stray field intensity.
Published: 2019

13. Phase detection limits in off-axis electron holography from pixelated detectors: gain variations, geometric distortion and failure of reference-hologram correction

Author: Martin Hÿtch, Christophe Gatel, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Université Fédérale Toulouse Midi-Pyrénées, Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and Université de Toulouse (UT)
Subjects: Phase (waves), Holography, Physics::Optics, 02 engineering and technology, 01 natural sciences, Noise (electronics), Phase detector, Electron holography, law.invention, Optics, Interference (communication), Structural Biology, law, 0103 physical sciences, Phase noise, Radiology, Nuclear Medicine and imaging, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Physics, business.industry, Detector, 021001 nanoscience & nanotechnology, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, business
Abstract: We investigate the effect that recording off-axis electron holograms on pixelated detectors, such as charge-coupled devices (CCD) and direct-detection devices (DDD), can have on measured amplitudes and phases. Theory will be developed for the case of perfectly uniform interference fringes illuminating an imperfect detector with gain variations and pixel displacements. We will show that both these types of defect produce a systematic noise in the phase images that depends on the position of the holographic fringes with respect to the detector. Subtracting a reference hologram from the object hologram will therefore not remove the phase noise if the initial phases of the two holograms do not coincide exactly. Another finding is that pi-shifted holograms are much less affected by gain variations but show no improvement concerning geometric distortions. The resulting phase errors will be estimated and simulations presented that confirm the theoretical developments.
Published: 2021

14. Synthesis of magnetic Fe and Co nano-whiskers and platelets via physical vapor deposition

Author: Gunther Richter, Zi-An Li, Christophe Gatel, and Wenting Huang
Subjects: Materials science, Whiskers, 02 engineering and technology, Crystal structure, Single domain, 010402 general chemistry, 01 natural sciences, Electron holography, Whisker, Nano, General Materials Science, Materials of engineering and construction. Mechanics of materials, Engineering & allied operations, Magnetic vortex, Mechanical Engineering, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Crystallography, Mechanics of Materials, Physical vapor deposition, TA401-492, ddc:620, Magnetic nanowires, 0210 nano-technology, Single crystal
Abstract: Fe and Co nano-whiskers and Co platelets were synthesized via physical vapor deposition without any template and catalyst. Transmission electron microscopic analyses revealed that the Fe whiskers were all single crystal with whisker axis along [1 0 0] crystallographic direction. Both FCC and HCP crystal structures were found in the Co whiskers with stacking faults and micro-twins. Off-axis Electron holography results showed that all the whiskers synthesized were magnetic single domain structures. Vortex state was observed in a small platelet of high symmetry.
Published: 2021

15. Customized MFM probes based on magnetic nanorods

Author: Javier Pablo-Navarro, Agustina Asenjo, Etienne Snoeck, César Magén, Pablo Ares, Julio Gómez-Herrero, Aurélien Masseboeuf, Christophe Gatel, Eider Berganza, Miriam Jaafar, José María de Teresa, Ministerio de Economía y Competitividad (España), Comunidad de Madrid, Ministerio de Ciencia, Innovación y Universidades (España), Universidad Autónoma de Madrid, Agencia Estatal de Investigación (España), Gobierno de Aragón, European Commission, Laboratorio de microscopias avanzadas (LMA), University of Zaragoza - Universidad de Zaragoza [Zaragoza], Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, Fabrication, Materials science, business.industry, Resolution (electron density), Demagnetizing field, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Sputtering, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], 0103 physical sciences, Perpendicular, [CHIM.CRIS]Chemical Sciences/Cristallography, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, General Materials Science, Nanorod, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Electron beam-induced deposition, Magnetic force microscope, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS
Abstract: Focused Electron Beam Induced Deposition (FEBID) for magnetic tip fabrication is presented in this work as an alternative to conventional sputtering-based Magnetic Force Microscopy (MFM) tips. FEBID enables the growth of a high-aspect-ratio magnetic nanorod with customized geometry and composition to overcome the key technical limitations of MFM probes currently on the market. The biggest advantage of these tips, in comparison with CoCr coated pyramidal probes, lies in the capability of creating sharp ends, nearly 10 nm in diameter, which provides remarkable (topographic and magnetic) lateral resolution in samples with magnetic features close to the resolution limits of the MFM technique itself. The shape of the nanorods produces a very confined magnetic stray field, whose interaction with the sample is extremely localized and perpendicular to the surface, with negligible in-plane components. This effect can lead to a better analytical and numerical modelling of the MFM probes and to an increase in the sensitivity without perturbing the magnetic configuration of soft samples. Besides, the high-aspect ratio achievable in FEBID nanorod tips makes them magnetically harder than the commercial ones, reaching coercive fields higher than 900 Oe. According to the results shown, tips based on magnetic nanorods grown by FEBID can be eventually used for quantitative analysis in MFM measurements. Moreover, the customized growth of Co- or Fe-based tips onto levers with different mechanical properties allows MFM studies that demand different measuring conditions. To showcase the versatility of this type of probe, as a last step, MFM is performed in a liquid environment, which still remains a challenge for the MFM community largely due to the lack of appropriate probes on the market. This opens up new possibilities in the investigation of magnetic biological samples., M. J., E. B. and A. A. acknowledge the support from the Spanish Ministry of Economy and Competitiveness (MINECO) under project nos. MAT2015-73775-JIN and MAT2016-76824-C3-1-R. M. J. and J. G.-H acknowledge financial support from the Spanish Ministry of Economy and Competitiveness through The “María de Maeztu” Programme for Units of Excellence in R&D (MDM-2014-0377). M. J. also acknowledges financial support from the Universidad Autónoma de Madrid and Comunidad Autónoma de Madrid through the project SI1/PJI/2019-00055. J. P.-N., C. M. and J. M. D. T. acknowledge financial support from the Spanish MINECO through the projects MAT2017-82970-C2-1-R, MAT2017-82970-C2-2-R and RED2018-102627-T, from the Aragon Regional Government (Construyendo Europa desde Aragón) through the project E13_20R with European Social Fund funding. This project has received funding from the European's Union Horizon 2020 research and innovation programme under Grant No. 823717-ESTEEM3. J. P.-N. grant is funded by the Ayuda para Contratos Predoctorales para la Formación de Doctores (BES-2015-072950) of the Spanish MINECO with the participation of the European Social Fund.
Published: 2020

16. Exotic Transverse-Vortex Magnetic Configurations in CoNi Nanowires

Author: Cristina Bran, Christophe Gatel, Ingrid Marie Andersen, Cécile Marcelot, Luis A. Rodríguez, Etienne Snoeck, Manuel Vázquez, Teresa Hungria, Sébastien Joulie, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Instituto de Ciencia de Materiales de Madrid – CSIC, 28049 Madrid, Spain, Centro de Excelencia en Nuevos Materiales, Universidad del Valle, A.A. 25360, Cali, Colombia, ANR-10-EQPX-0038,MIMETIS,Microscopie Interférométrique et Microscopie Electronique en Transmission In Situ(2010), ANR-17-CE24-0047,IODA,Microscopie électronique in operando pour l'analyse de composants(2017), European Project: 823717,ESTEEM3, Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Centro de Excelencia en Nuevos Materiales, Universidad del Valle [Cali] (Univalle), Centre de microcaractérisation Raimond Castaing (Centre Castaing), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)
Subjects: Materials science, electron holography, Nanowire, FOS: Physical sciences, General Physics and Astronomy, Physics::Optics, Applied Physics (physics.app-ph), 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Electron holography, Condensed Matter::Materials Science, magnetic configuration, vortex state, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Perpendicular, [CHIM.CRIS]Chemical Sciences/Cristallography, General Materials Science, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], micromagnetic simulation, ComputingMilieux_MISCELLANEOUS, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed matter physics, nanocylinder, General Engineering, Close-packing of equal spheres, Physics - Applied Physics, 021001 nanoscience & nanotechnology, Vortex state, 0104 chemical sciences, Vortex, Magnetic anisotropy, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Grain boundary, magnetic nanowire, 0210 nano-technology
Abstract: The magnetic configurations of cylindrical Co-rich CoNi nanowires have been quantitatively analyzed at the nanoscale by electron holography and correlated to local structural and chemical properties. The nanowires display grains of both face-centered cubic (fcc) and hexagonal close packed (hcp) crystal structures, with grain boundaries parallel to the nanowire axis direction. Electron holography evidences the existence of a complex exotic magnetic configuration characterized by two distinctly different types of magnetic configurations within a single nanowire: an array of periodical vortices separating small transverse domains in hcp-rich regions with perpendicular easy axis orientation and a mostly axial configuration parallel to the nanowire axis in regions with fcc grains. These vastly different domains are found to be caused by local variations in the chemical composition modifying the crystalline orientation and/or structure, which give rise to change in magnetic anisotropies. Micromagnetic simulations, including the structural properties that have been experimentally determined, allow for a deeper understanding of the complex magnetic states observed by electron holography.
Published: 2020

17. One-Pot Seed-Mediated Growth of Co Nanoparticles by the Polyol Process: Unraveling the Heterogeneous Nucleation

Author: Jean-Yves Piquemal, Christophe Gatel, Guillaume Viau, Martin Hÿtch, Raj Kumar Ramamoorthy, Arnaud Viola, Bilel Grindi, Jennifer Peron, Raul Arenal, L. Sicard, Marion Giraud, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS (UMR_7086)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM ICMMM), Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), University of Zaragoza - Universidad de Zaragoza [Zaragoza], Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paris Diderot - Paris 7 (UPD7)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Agence Nationale de la Recherche (France), Ministerio de Economía y Competitividad (España), European Commission, Gatel, Christophe, Arenal, Raul, Giraud, Marion, Viau, Guillaume, Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Université Montpellier 1 (UM1)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Gatel, Christophe [0000-0001-5549-7008], Arenal, Raul [0000-0002-2071-9093], Giraud, Marion [0000-0003-1810-7626], and Viau, Guillaume [0000-0001-7062-4183]
Subjects: chemistry.chemical_classification, Materials science, Geometric phase analysis, Mechanical Engineering, Nucleation, Nanoparticle, Bioengineering, Good control, 02 engineering and technology, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Polyol, chemistry, Chemical engineering, Cobalt nanoparticles, Polyol synthesis, Scientific method, Particle, General Materials Science, Seed mediated, HAADF-STEM, 0210 nano-technology, Metal nanoparticles
Abstract: The one-step seed-mediated synthesis is widely used for the preparation of ferromagnetic metal nanoparticles (NPs) since it offers a good control of particle morphology. Nevertheless, this approach suffers from a lack of mechanistic studies because of the difficulties of following in real time the heterogeneous nucleation and predicting structure effects with seeds that are generated in situ. Here, we propose a complete scheme of the heteronucleation process involved in one-pot seed-mediated syntheses of cobalt nanoparticles in liquid polyols, relying on geometrical phase analysis (GPA) of high-resolution high-angle annular dark field (HAADF)-STEM images and in situ measurements of the molecular hydrogen evolution. Cobalt particles of different shapes (rods, platelets, or hourglass-like particles) were grown by reducing cobalt carboxylate in liquid polyols in the presence of iridium or ruthenium chloride as the nucleating agent. A reaction scheme was established by monitoring the H2 evolution resulting from the decomposition of metal hydrides, formed in situ by β-elimination of metal alkoxides, and from the polyol dehydrogenation, catalytically activated by the metal particles. This is a very good probe for both the noble metal nucleation and the heterogeneous nucleation of cobalt, showing a good separation of these two steps. Ir and Ru seeds with a size in the range 1–2 nm were found exactly in the center of the cobalt particles, whatever the cobalt particle shape, and high-resolution images revealed an epitaxial growth of the hcp Co on fcc Ir or hcp Ru seeds. The microstructure analysis around the seeds made evident two different ways of relaxing the lattice mismatch between the seeds and the cobalt, with the presence of dislocations around the Ir seeds and compression zones of the cobalt lattice near the Ru seeds. The relationship between the nature of the nucleating agent, the reaction steps, and the microstructure is discussed., This work was funded by the French National Research Agency, ANR, in the framework of the TANOPOL project (ANR-15-CE07-0011-01). Angélique Gillet is warmly thanked for the nanoparticle synthesis, and Lucien Datas and Teresa Hungria (Plateforme Castaing, Toulouse) are thanked for HAADF-STEM images. We gratefully acknowledge the International Associated Laboratory (LIA)-M2ZART for financial support. High-resolution HAADF-STEM images were performed at the Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Spain. R.A. gratefully acknowledges the support from the Spanish Ministry of Economy and Competitiveness (MINECO) through Project MAT2016-79776-P (AEF/FEDER. UE) and from the European Union H2020 program “ESTEEM3” (823717).
Published: 2019

18. Multi magnetic states in Co/Cu multilayered cylindrical nanowires studied by combination of off-axis electron holography imaging and micromagnetic simulations

Author: Nicolas Biziere, Christophe Gatel, David Fernando Reyes Vasquez, T. Wade, Bénédicte Warot-Fonrose, Matériaux et dispositifs pour l'Electronique et le Magnétisme (CEMES-MEM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Laboratoire des Solides Irradiés (LSI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3)
Subjects: 010302 applied physics, Materials science, Condensed matter physics, Nanowire, General Physics and Astronomy, [CHIM.MATE]Chemical Sciences/Material chemistry, 02 engineering and technology, 021001 nanoscience & nanotechnology, Magnetocrystalline anisotropy, 01 natural sciences, Electron holography, Magnetization, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], 0103 physical sciences, 0210 nano-technology, Anisotropy, Saturation (magnetic), Magnetic dipole–dipole interaction, ComputingMilieux_MISCELLANEOUS, Phase diagram
Abstract: International audience; We report on a wide variety of magnetic states in Co/Cu multilayered nanocylinders grown by electrodeposition with different thicknesses of both elements. The remnant magnetic states in individual Co layers have quantitatively been determined at the nanoscale by micromagnetic reconstruction of the magnetic phase shift image obtained by electron holography. We demonstrate that the magnetization in the Co layers can present either uniform or vortex states. Also, different magnetic configurations can be observed within the same nanocylinder. In the case of vortices, the direction of the core can rotate almost at 90° from the nanocylinder axis for layers with aspect ratio close to 1. We show that the occurrence of each magnetic configuration depends on the aspect ratio of the layers, the direction of magnetocrystalline anisotropy and in some cases on the interlayer dipolar coupling. Such a wide variety of magnetic states are observed due to lower values of the Co magnetic constants (magnetization, exchange, anisotropy) with respect to bulk, typical of electrodeposition process in a single bath, and to the local geometrical variation of the layers. We also calculated the phase diagram of the remnant magnetic states in a single layer for various amplitudes and orientations of the magnetocrystalline anisotropy and different directions of the saturation field. In particular cases, these phase diagrams in addition to statistics of occurrence of each kind of magnetic configurations in the multilayer and the application of a saturation field in different directions allows recovering information on the preferential orientation of the crystalline anisotropy.
Published: 2019

19. Nanoparticle Ripening : A Versatile Approach for the Size and Shape Control of Metallic Iron Nanoparticles

Author: Sébastien Lachaize, Pier-Francesco Fazzini, Bruno Chaudret, Anca Meffre, Lise-Marie Lacroix, Christophe Gatel, Marc Respaud, Laboratoire de physique et chimie des nano-objets (LPCNO), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Materials science, Nucleation, Nanoparticle, 010402 general chemistry, 01 natural sciences, Corrosion, Metal, Palmitic acid, chemistry.chemical_compound, iron, Mössbauer spectroscopy, Moessbauer spectroscopy, Dissolution, Coalescence (physics), [PHYS]Physics [physics], 010405 organic chemistry, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 0104 chemical sciences, Chemical engineering, chemistry, visual_art, visual_art.visual_art_medium, seeded growth, nanoparticles, magnetic properties
Abstract: International audience; A novel approach for the synthesis of Fe(0) nanoparticles (NPs) with tunable sizes and shapes is reported. Ultrasmall Fe(0) NPs were reacted under mild conditions in the presence of a mixture of palmitic acid and amine ligands. These NPs acted not only as preformed seeds but also as an internal iron(II) source that was produced by the partial dissolution of the NPs by the acid. This fairly simple approach allows a strict separation between the nucleation and the growth steps. By changing the acid concentration, a fine tuning of the relative ratio between remaining Fe(0) seeds and iron(II) reservoir was achieved, giving access to both size (from 7 to 20 nm) and a shape (spheres, cubes or stars) control. The partial dissolution of the ultrasmall Fe(0) NPs into iron(II) source and the successive growth was further studied by using combined TEM and Mössbauer spectroscopy. The successive corrosion, coalescence, and ripening observed could be understood in the framework of an environment-dependent growth model.
Published: 2019

20. Optimization of off-axis electron holography performed with femtosecond electron pulses

Author: Giuseppe Mario Caruso, Florent Houdellier, Martin Hÿtch, Christophe Gatel, Sébastien J. Weber, Arnaud Arbouet, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Materials science, electron holography, [PHYS.PHYS.PHYS-ACC-PH]Physics [physics]/Physics [physics]/Accelerator Physics [physics.acc-ph], Holography, Phase (waves), Physics::Optics, 02 engineering and technology, Electron, 01 natural sciences, Electron holography, law.invention, [SPI.MAT]Engineering Sciences [physics]/Materials, Optics, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], law, femtosecond laser, 0103 physical sciences, cold field emission, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Field emission gun, Instrumentation, 010302 applied physics, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Transmission electron microscopy, Femtosecond, Ultrafast Transmission Electron Microscopy, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, 0210 nano-technology, business, Ultrashort pulse, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; We report on electron holography experiments performed with femtosecond electron pulses in an ultrafast coherent Transmission Electron Microscope based on a laser-driven cold field emission gun. We first discuss the experimental requirements related to the long acquisition times imposed by the low emission/probe current available in these instruments. The experimental parameters are first optimized and electron holograms are then acquired in vacuum and on a nano-object showing that useful physical properties can nevertheless be extracted from the hologram phase in pulsed condition. Finally, we show that the acquisition of short exposure time holograms assembled in a stack, combined with a computer-assisted shift compensation of usual instabilities encountered in holography, such as beam and biprism wire instabilities, can yield electron holograms acquired with a much better contrast paving the way to ultrafast time-resolved electron holography.
Published: 2019

21. Holographic vector field electron tomography of three-dimensional nanomagnets

Author: Daniel Wolf, Nicolas Biziere, Sebastian Sturm, David Reyes, Travis Wade, Tore Niermann, Jonas Krehl, Benedicte Warot-Fonrose, Bernd Büchner, Etienne Snoeck, Christophe Gatel, Axel Lubk
Published: 2019
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22. Quantitative Nanoscale Magnetic Study of Isolated Diameter-Modulated FeCoCu Nanowires

Author: Cristina Bran, Manuel Vázquez, Etienne Snoeck, David Reyes, Christophe Gatel, Eider Berganza, Luis Alfredo Rodriguez, Agustina Asenjo, Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Materials science, Magnetic domain, Nanowire, General Physics and Astronomy, Nanotechnology, 02 engineering and technology, 01 natural sciences, Electron holography, Magnetization, 0103 physical sciences, [CHIM.CRIS]Chemical Sciences/Cristallography, General Materials Science, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], ComputingMilieux_MISCELLANEOUS, 010302 applied physics, Spin configuration, Condensed matter physics, Demagnetizing field, General Engineering, 021001 nanoscience & nanotechnology, Magnetic charges, Magnetic imaging, Magnetic field, Domain wall (magnetism), [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Magnetic force microscope, Magnetic nanowires, 0210 nano-technology, Micromagnetic simulations
Abstract: The comprehension of the magnetic configuration in FeCoCu nanowires with a diameter-modulated cylindrical geometry will allow controlling the domain wall motion in this low-dimensional system under the application of magnetic fields and/or the injection of current pulses. Here we perform a quantitative magnetic characterization of isolated diameter-modulated FeCoCu nanowires by combining nanoscale magnetic characterization techniques such as electron holography, magnetic force microscopy, and micromagnetic simulations. Local reconstructions of the magnetic distribution show the diameter-modulated geometry of the wires induces the formation of vortex-like structures and magnetic charges in the regions where the diameter is varied. Vortex-like structures modify the axial alignment of the magnetization in large-diameter segments. Moreover, the magnetic charges control the demagnetizing field distribution, promoting a flux-closure stray field configuration around large-diameter segments and keeping the demagnetizing field parallel to the NW's magnetization around small diameter segments. The detailed description of the remanent state in diameter-modulated cylindrical FeCoCu nanowires allows us to provide a clear explanation of the origin of bright and dark contrast observed in magnetic force microscopy images, which have the same feature of magnetic domain walls. This work establishes the primary knowledge required for future magnetization reversal studies with the aim of searching efficient modulated geometries that allow an optimum and controlled domain wall propagation.
Published: 2016

23. Unlimited acquisition time in electron holography by automated feedback control of transmission electron microscope

Author: Florent Houdellier, Martin Hÿtch, Julien Dupuy, Christophe Gatel, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and ANR-17-CE24-0047,IODA,Microscopie électronique in operando pour l'analyse de composants(2017)
Subjects: Physics and Astronomy (miscellaneous), Computer science, [PHYS.PHYS.PHYS-ACC-PH]Physics [physics]/Physics [physics]/Accelerator Physics [physics.acc-ph], Holography, 02 engineering and technology, Electron, 01 natural sciences, Electron holography, law.invention, [SPI.MAT]Engineering Sciences [physics]/Materials, Optics, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], law, Position (vector), 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], ComputingMilieux_MISCELLANEOUS, 010302 applied physics, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, 021001 nanoscience & nanotechnology, Automation, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Transmission electron microscopy, Computer data storage, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Tomography, 0210 nano-technology, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: The signal-to-noise ratio of measurements by electron holography could be considerably improved if longer exposure times were possible: increasing the number of electrons contributing to the hologram improves the counting statistics. However, instrumental instabilities causing drift in the hologram fringes and specimen position make acquisition times of above a few seconds counterproductive. The current approach is to acquire image stacks of holograms, with short exposure times, followed by numerical realignment through sophisticated post-processing. The associated data storage and manipulation make in-situ and tomography experiments extremely cumbersome. Here, we implement dynamic automation of electron holography experiments to overcome these problems. The real-time drift measurement and feedback control of the instrument allow single holograms to be acquired with exposure times of 30 min or more. Indeed, there are no longer any limitations from instrumental instabilities and only those imposed by the specimen itself. Furthermore, automation allows the implementation of sophisticated phase reconstruction techniques based on precise control of the experimental conditions. Smart acquisition of electron holograms preludes future computer-controlled electron microscopy capabilities.The signal-to-noise ratio of measurements by electron holography could be considerably improved if longer exposure times were possible: increasing the number of electrons contributing to the hologram improves the counting statistics. However, instrumental instabilities causing drift in the hologram fringes and specimen position make acquisition times of above a few seconds counterproductive. The current approach is to acquire image stacks of holograms, with short exposure times, followed by numerical realignment through sophisticated post-processing. The associated data storage and manipulation make in-situ and tomography experiments extremely cumbersome. Here, we implement dynamic automation of electron holography experiments to overcome these problems. The real-time drift measurement and feedback control of the instrument allow single holograms to be acquired with exposure times of 30 min or more. Indeed, there are no longer any limitations from instrumental instabilities and only those imposed by the s...
Published: 2018

24. Platinum tripods as nanometric frequency multiplexing devices

Author: Benjamin Lassagne, B. C. Camargo, Walter Escoffier, Lise-Marie Lacroix, Thomas Blon, Guillaume Viau, Christophe Gatel, Raul Arenal, Polish Academy of Sciences (PAN), Laboratoire national des champs magnétiques intenses - Toulouse (LNCMI-T), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Laboratorio de Microscopias Avanzadas, University of Zaragoza - Universidad de Zaragoza [Zaragoza], Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratorio de microscopias avanzadas (LMA), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)
Subjects: Materials science, chemistry.chemical_element, FOS: Physical sciences, Nanotechnology, 02 engineering and technology, Crystal structure, 010402 general chemistry, 01 natural sciences, Multiplexer, Frequency-division multiplexing, Metal, chemistry.chemical_compound, Oleylamine, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Microelectronics, General Materials Science, [CHIM.COOR]Chemical Sciences/Coordination chemistry, [PHYS]Physics [physics], Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics, business.industry, Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, 0104 chemical sciences, Characterization (materials science), chemistry, visual_art, visual_art.visual_art_medium, 0210 nano-technology, business, Platinum
Abstract: International audience; Electrical and structural characterization studies of nano-particles are very important steps to determine their potential applications in microelectronics. In this paper, we address the crystallographic and electric transport properties of soft-chemistry-grown nanometric Pt tribranches. We report that Pt nanostars grown from the reduction of H2PtCl6 salt in pure oleylamine present a remarkable crystalline structure and deeply metallic character despite being grown under mild conditions. We demonstrate that such devices are able to operate at current densities surpassing 200 MA cm−2, actuating as highly compact frequency multiplexers in the non-ohmic regime.
Published: 2018

25. Off-axis electron holography for the quantitative study of magnetic properties of nanostructures: from the single nanomagnet to the complex device

Author: Marie-José Casanove, Aurélien Masseboeuf, Nicolas Biziere, Bénédicte Warot-Fonrose, Lise-Marie Lacroix, Christophe Gatel, Thomas Blon, A. Meffre, and F.B. Bonilla
Subjects: Magnetization, Phase transition, Materials science, Spintronics, Condensed matter physics, Magnetic nanoparticles, Single domain, Magnetic force microscope, Nanomagnet, Vortex state
Abstract: Electromagnetic properties are one of the keys for understanding and mastering nano systems used in many applications, as in medical treatment, optics, microelectronic or data storage. Various methods exist to map magnetic fields. Some are based on near field microscopy, like magnetic force microscopy, other on X-ray set-ups, like photoemission electron microscopy. Electron holography (EH), a powerful transmission electron microscopy method, is another appropriate tool which combines high sensitivity with a high spatial resolution. EH allow the quantitative measurement of both internal and external fields in individual nano-objects instead of assemblies of nanoobjects. This interferometric method can also be used for performing in situ/in operando experiments. We thus developed and applied EH on very different systems, from the single nanoparticles to the thin layer and the complex magnetic device, for studying their magnetic properties. In this presentation, we will present our investigations on a single Fe nanocube and an FeRh thin layer. - Nanomagnets recently attracted considerable interest due to their possible application as building blocks for hard drive disks and permanent magnets or as nanobiological vectors for drug delivery and hyperthermia. Despite theoretical studies, the size-dependence of spin arrangements in single nanomagnets has not yet been evidenced experimentally due to sensitivity limitations of the investigation tools. The single domain limit, corresponding to the critical nanomagnet size separating vortex/single domain configurations, has never been observed although it will dictate the optimized size for applications. In such small nano-objects, micromagnetic simulations show that the magnetic internal structure changes from single domain (SD) to vortex states as the cube size increases (Fig. 1). Some years ago, we reported symmetrical vortices, i.e. vortex of axis, in isolated 30 nm single crystal Fe cubes with a 14 nm vortex core size [2]. Next, we showed that vortices can also be stabilized in the presence of dipolar interactions thanks to holes in the cubes inducing a pinning of the vortex core [3]. Here we will present the spin configuration phase diagram in size-controlled single Fe nanocubes combining EH experiments and micromagnetic simulations [4]. High sensitivity imaging explicitly reveals how three different spin arrangements can be stabilized within a 3 nm window, evidencing the key importance of nanometric size control of magnetic nanoparticles. Moreover, it gives a deeper understanding of the single domain limit, which is more complex than expected with the appearance of a previously unreported vortex state. Such a measurement opens the door to fine magnetic control of nano-objects. - In situ heating/cooling EH has been used to quantitatively map the magnetization of a cross-sectional FeRh thin film through its magnetic transition [5]. This alloy presents a remarkable and unusual magnetic transition from a low temperature antiferromagnetic state (AFM) to a high temperature ferromagnetic state (FM) close to 370K accompanied by a 1% volume expansion. [6- 8]The transition is obtained for a narrow composition range 0.48
Published: 2018

26. Air-Stable Anisotropic Monocrystalline Nickel Nanowires Characterized Using Electron Holography

Author: Alfonso Ibarra, Myrtil L. Kahn, Pier-Francesco Fazzini, Glenna L. Drisko, Christophe Gatel, Katia Fajerwerg, Stefanos Mourdikoudis, Pierre Fau, Vincent Bley, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Laboratoire de physique et chimie des nano-objets (LPCNO), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratorio de microscopias avanzadas (LMA), University of Zaragoza - Universidad de Zaragoza [Zaragoza], Healthcare Biomagnetic and Nanomaterials Laboratories, University College of London [London] (UCL), Matériaux Diélectriques dans la Conversion d’Energie (LAPLACE-MDCE), LAboratoire PLasma et Conversion d'Energie (LAPLACE), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), the RTRA Sciences et Technologies pour l’Aéronautique et l’Espace, the Investissements d’Avenir program is run by the French Agence Nationale de la Recherche. A.I. thanks the Gobierno de Aragón (Grant E81) and Fondo Social Europeo., ANR-10-IDEX-0003,IDEX BORDEAUX,Initiative d'excellence de l'Université de Bordeaux(2010), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Laboratorio de Microscopias Avanzadas, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées
Subjects: Materials science, Magnetism, Composite number, Nanowire, chemistry.chemical_element, Bioengineering, Crystal growth, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, 7. Clean energy, Electron holography, Monocrystalline silicon, Nickel, General Materials Science, Composite material, Electric discharge, Nanowires, Mechanical Engineering, Ligand stabilization, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, chemistry, Ferromagnetism, 0210 nano-technology
Abstract: International audience; Nickel is capable of discharging electric and magnetic shocks in aerospace materials thanks to its conductivity and magnetism. Nickel nanowires are especially desirable for such an application as electronic percolation can be achieved without significantly increasing the weight of the composite material. In this work, single-crystal nickel nanowires possessing a homogeneous magnetic field are produced via a metal–organic precursor decomposition synthesis in solution. The nickel wires are 20 nm in width and 1–2 μm in length. The high anisotropy is attained through a combination of preferential crystal growth in the ⟨100⟩ direction and surfactant templating using hexadecylamine and stearic acid. The organic template ligands protect the nickel from oxidation, even after months of exposure to ambient conditions. These materials were studied using electron holography to characterize their magnetic properties. These thin nanowires display homogeneous ferromagnetism with a magnetic saturation (517 ± 80 emu cm–3), which is nearly equivalent to that of bulk nickel (557 emu cm–3). Nickel nanowires were incorporated into carbon composite test pieces and were shown to dramatically improve the electric discharge properties of the composite material.
Published: 2018

27. Probing domain walls in cylindrical magnetic nanowires with electron holography

Author: Aurélien Masseboeuf, Jean-Christophe Toussaint, Olivier Fruchart, Ségolène Jamet, Julien Bachmann, Christophe Gatel, Sebastian Bochmann, Michal Staňo, Micro et NanoMagnétisme (MNM ), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ANR-10-LABX-0051,LANEF,Laboratory of Alliances on Nanosciences - Energy for the Future(2010), European Project: 309589,EC:FP7:NMP,FP7-NMP-2012-SMALL-6,M3D(2012), Micro et NanoMagnétisme (NEEL - MNM), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: History, Condensed Matter - Materials Science, Materials science, Magnetic domain, Condensed matter physics, Nanowire, Holography, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, 02 engineering and technology, Electron, 021001 nanoscience & nanotechnology, Electrostatics, 01 natural sciences, Electron holography, Computer Science Applications, Education, law.invention, Transverse plane, Domain wall (magnetism), law, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 010306 general physics, 0210 nano-technology
Abstract: We probe magnetic domain walls in cylindrical soft magnetic nanowires using electron holography. We detail the modelling of expected contrast for both transverse and Bloch point domain walls and provide comparison with experimental observations performed on NiCo nanowires, involving also both magnetic and electrostatic contribution to the electron holography map. This allows the fast determination of the domain wall type without the need for uneasy and time-consuming experimental removal of the electrostatic contribution. Finally, we describe and implement a new efficient algorithm for calculating the magnetic contrast., Comment: 3 pages, 2 figures
Published: 2017

28. Chiral magnetic monopoles in artificial spin systems (Conference Presentation)

Author: Manijeh Razeghi, Van Dau Frederic Nguyen, Michel Hehn, Nicolas Rougemaille, Benito Santos Burgos, D. Lacour, Ioan A. Chioar, Andrea Locatelli, Benjamin Canals, H. Riahi, Aurélien Masseboeuf, Yann Perrin, Henri-Jean Drouhin, Tevfik Onur Menteş, Stefan McMurtry, François Montaigne, Henri Jaffrès, Jean-Christophe Toussaint, Christophe Gatel, and Jean-Eric Wegrowe
Subjects: Physics, Presentation, Condensed matter physics, business.industry, media_common.quotation_subject, Electrical engineering, Magnetic monopole, business, media_common, Spin-½
Published: 2017

29. Role of internal demagnetizing field for the dynamics of a surface-modulated magnonic crystal

Author: Falk Röder, Jürgen Lindner, S. Stienen, P. Landeros, T. Schneider, Lothar Bischoff, Christophe Gatel, Kilian Lenz, Jürgen Fassbender, R. A. Gallardo, René Hübner, M. Langer, Institute of Ion Beam Physics and Materials Research [Dresden], Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Universidad Tecnica Federico Santa Maria [Valparaiso] (UTFSM), Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, [PHYS]Physics [physics], Field (physics), Condensed matter physics, Band gap, Demagnetizing field, 02 engineering and technology, 021001 nanoscience & nanotechnology, Rotation, 01 natural sciences, Electron holography, Crystal, Spin wave, Modulation, 0103 physical sciences, Condensed Matter::Strongly Correlated Electrons, 010306 general physics, 0210 nano-technology
Abstract: International audience; Magnonic crystals with locally alternating properties and specific periodicities exhibit interesting effects, such as a multitude of different spin-wave states and large band gaps. This work aims for demonstrating and understanding the key role of local demagnetizing fields in such systems. To achieve this, hybrid structures are investigated consisting of a continuous thin film with a stripe modulation on top favorable due to the adjustability of the magnonic effects with the modulation size. For a direct access to the spin dynamics, a magnonic crystal was reconstructed from 'bottom-up', i.e., the structural shape as well as the internal field landscape of the structure were experimentally obtained on the nanoscale using electron holography. Subsequently, both properties were utilized to perform dynamic response calculations. The simulations yield the frequency-field dependence as well as the angular dependence of spin waves in a magnonic crystal and reveal the governing role of the internal field landscape around the backward-volume geometry. The complex angle-dependent spin-wave behavior is described for a 360 • in-plane rotation of an external field by connecting the internal field landscape with the individual spin-wave localization.
Published: 2017

30. In Depth Spatially Inhomogeneous Phase Transition in Epitaxial MnAs Film on GaAs(001)

Author: Mahmoud Eddrief, Virginie Serin, Xiaoxiao Fu, Bénédicte Warot-Fonrose, Victor H. Etgens, Christophe Gatel, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Matériaux Multi-fonctionnels et Multi-échelles (CEMES-M3), Croissance et propriétés de systèmes hybrides en couches minces (INSP-E8), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ingénierie des Systèmes de Versailles (LISV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Phase transition, Work (thermodynamics), Structural phase, Materials science, thin film, Bioengineering, 02 engineering and technology, Epitaxy, 01 natural sciences, in situ TEM, Electron holography, 0103 physical sciences, General Materials Science, Thin film, 010306 general physics, Condensed matter physics, Mechanical Engineering, General Chemistry, MnAs, 021001 nanoscience & nanotechnology, Condensed Matter Physics, phase transition, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], magnetic materials, Nanometre, 0210 nano-technology, Layer (electronics)
Abstract: International audience; Most studies on MnAs material in its bulk form have been focused on its temperature-dependent structural phase transition accompanied by a magnetic one. Magnetostructural phase transition parameters in thin MnAs films grown on substrates present however some differences from the bulk behavior, and local studies become mandatory for a deeper understanding of the mechanisms involved within the transition. Up to now, only surface techniques have been carried out, while the transition is a three-dimensional phenomenon. We therefore developed an original nanometer scale methodology using electron holography to investigate the phase transition in an epitaxial MnAs thin film on GaAs(001) from the cross-section view. Using quantitative magnetic maps recorded at the nanometer scale as a function of the temperature, our work provides a direct in situ observation of the inhomogeneous spatial distribution of the transition in the layer depth and brings new insights on the fundamental transition mechanisms.
Published: 2017

31. Optimising electron microscopy experiment through electron optics simulation

Author: Christophe Gatel, Y Kubo, Etienne Snoeck, Florent Houdellier, Quantronics Group (QUANTRONICS), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: 010302 applied physics, Physics, [PHYS]Physics [physics], Microscope, business.industry, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, law.invention, Lens (optics), Field electron emission, Optics, Transmission electron microscopy, law, Electron optics, 0103 physical sciences, Electron microscope, 0210 nano-technology, High-resolution transmission electron microscopy, Field emission gun, business, Instrumentation
Abstract: International audience; We developed a new type of electron trajectories simulation inside a complete model of a modern transmission electron microscope (TEM). Our model incorporates the precise and real design of each element constituting a TEM, i.e. the field emission (FE) cathode, the extraction optic and acceleration stages of a 300 kV cold field emission gun, the illumination lenses, the objective lens, the intermediate and projection lenses. Full trajectories can be computed using magnetically saturated or non-saturated round lenses, magnetic deflectors and even non-cylindrical symmetry elements like electrostatic biprism. This multi-scale model gathers nanometer size components (FE tip) with parts of meter length (illumination and projection systems). We demonstrate that non-trivial TEM experiments requiring specific and complex optical configurations can be simulated and optimized prior to any experiment using such model. We show that all the currents set in all optical elements of the simulated column can be implemented in the real column (I2TEM in CEMES) and used as starting alignment for the requested experiment. We argue that the combination of such complete electron trajectory simulations in the whole TEM column with automatic optimization of the microscope parameters for optimal experimental data (images, diffraction, spectra) allows drastically simplifying the implementation of complex experiments in TEM and will facilitate the development of advanced use of the electron microscope in the near future.
Published: 2017

32. Inside a FeRh layer during the ferromagnetic/antiferromagnetic transition: a quantitative study by off-axis electron holography

Author: Christophe Gatel, Bénédicte Warot-Fonrose, Luis-Alfredo Rodriguez, David Reyes, Nicolas Biziere, Robin Cours, and Marie-José Casanove
Published: 2016

33. Developing new electron interferometry configurations in I2TEM thanks to electron optics simulations

Author: Yudai Kubo, Christophe Gatel, Yoshifumi Taniguchi, Etienne Snoeck, and Florent Houdellier
Published: 2016

34. Remnant states and magnetic coupling in Co/Cu multilayered nanowires observed by electron holography

Author: David Reyes, Luis Alfredo Rodríguez, Bénédicte Warot-Fonrose, Nicolas Biziere, Travis Wade, and Christophe Gatel
Published: 2016

35. Dynamical Holographic Moirés : Time average holographic interferometry

Author: Christophe Gatel, Aurélien Masseboeuf, Florent Houdellier, and Etienne Snoeck
Published: 2016

36. Crystal growth of bullet-shaped magnetite in magnetotactic bacteria of the Nitrospirae phylum

Author: Jinhua Li, Nicolas Menguy, Christophe Gatel, Victor Boureau, Etienne Snoeck, Eric Leroy, and Gilles Patriarche
Published: 2016

37. Strain at interfaces of the InAs/AlSb heterostructure for quantum cascade lasers

Author: Maxime Vallet, Yann Claveau, Bénédicte Warot-Fonrose, Christophe Gatel, Nicolas Combe, Cesar Magen, Roland Teissier, Alexei Baranov, and Anne Ponchet
Published: 2016

38. Electron interferometry techniques for strain analysis using a multi-biprism microscope

Author: Thibaud Denneulin, Falk Röder, Florent Houdellier, Christophe Gatel, Etienne Snoeck, and Martin Hÿtch
Subjects: 010302 applied physics, 0103 physical sciences, 02 engineering and technology, 021001 nanoscience & nanotechnology, 0210 nano-technology, 01 natural sciences
Published: 2016

39. Mapping 2D strain components from STEM moiré fringes

Author: Martin Hytch, Christophe Gatel, Akimitsu Ishizuka, and Kazuo Ishizuka
Published: 2016

40. Magnetic Configurations in Three-Dimensional Nanomagnets Explored by Electron Holographic Tomography

Author: Jonas Krehl, Etienne Snoeck, Christophe Gatel, Axel Lubk, Sebastian Sturm, and Daniel Wolf
Subjects: 0301 basic medicine, Materials science, business.industry, Holography, 02 engineering and technology, Electron, 021001 nanoscience & nanotechnology, Nanomagnet, law.invention, 03 medical and health sciences, 030104 developmental biology, Optics, law, Tomography, 0210 nano-technology, business, Instrumentation
Published: 2018

41. Complex magnetic distribution of diameter-modulated FeCoCu nanowires resolved by electron holography

Author: Luis Alfredo Rodríguez, Cristina Bran, David Reyes, Christophe Gatel, Eider Berganza, Manuel Vázquez, Agustina Asenjo, Etienne Snoeck, and European Commission
Subjects: 010302 applied physics, 0103 physical sciences, 02 engineering and technology, 021001 nanoscience & nanotechnology, 0210 nano-technology, 01 natural sciences, 3. Good health
Abstract: Oral presentation given at the 16th European Microscopy Congress, held in Lyon (France) from August 28th to September 2nd, 2016., In the last years, diameter-modulated (D-M) ferromagnetic nanowires (NWs) have been intensively studied to evaluate their efficiency to control the motion of domain walls (DWs) along these one-dimensional nanostructures by the application of magnetic field or the injection of electrical current, which is essential for spintronic applications in the field of information storage, sensors and logical operations [1]. Preliminary studies in D-M NWs have been performed using theoretical and experimental procedures [2-4] in individual and isolated NWs and they have provided a first approach of the spin configuration in these systems, obtaining a non-trivial interpretation. In this work, we have exploited the potential of electron holography technique (high spatial resolution, high sensitivity and quantitative capability in volume) for achieving a full picture of the magnetic distribution in cylindrical D-M FeCoCu NWs. These NWs were prepared by filling self-assembled cylindrical D-M nanochannels of anodic aluminum oxide templates. The D-M geometry of the polycrystalline NWs consist of alternating segments of small (100 nm) and large (144 nm) diameters, with segment lengths ranging between 1000 to 300 nm. At remanence, the high-shape anisotropy of the NWs induces a single-domain state where the spins are mainly oriented along the NW axis, with the possibility to create a small closure domain in large-diameter tips. The transition zones where the diameter is varied induce a complex demagnetizing field where the stray field follows a flux-closure configuration around the large-diameter segments and a magnetic coupling between them around small-diameter segments (See Fig 1). The complex configuration of the demagnetizing field can be understood if we treat the D-M transition zones as magnetic charges. The interpretation of the magnetic distribution by EH experiments was compared with micromagnetic simulation finding a very good agreement (see Fig 2). In addition, In-situ Lorentz microscopy experiments of the magnetization reversal process allowed evaluating the DW nucleation and propagate process by the application of magnetic fields. We found that a field-driven manipulation of DWs is not possible for the NWs in study. This “unsuccessful” result however helps us to take a step forward for the optimization of the geometry to reach the desired DW manipulation., This work has been supported by ESTEEM2 (Reference No. 312483), “Investissement d’Avenir” (Reference No. ANR-10-EQPX-38-01) and CPER programs.
Published: 2016

42. Elastic strains at interfaces in InAs/AlSb multilayer structures for quantum cascade lasers

Author: Christophe Gatel, Julien Nicolai, Anne Ponchet, Alexei N. Baranov, Bénédicte Warot-Fonrose, César Magén, Roland Teissier, Surfaces, Interfaces et Nano-Objets (CEMES-SINanO), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Composants à Nanostructure pour le moyen infrarouge (NANOMIR), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), University of Zaragoza - Universidad de Zaragoza [Zaragoza], ANR-11-BS10-0017,NAIADE,Nanocaractérisation et modélisation d'Antimoniures d'éléments III : Interfaces et Analyse des Déformations d'Epitaxie(2011), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, Materials science, Physics and Astronomy (miscellaneous), Condensed matter physics, Heterojunction, 02 engineering and technology, 021001 nanoscience & nanotechnology, Epitaxy, 01 natural sciences, Dark field microscopy, [SPI.TRON]Engineering Sciences [physics]/Electronics, Transmission electron microscopy, 0103 physical sciences, Microscopy, Scanning transmission electron microscopy, 0210 nano-technology, High-resolution transmission electron microscopy, ComputingMilieux_MISCELLANEOUS, Molecular beam epitaxy
Abstract: InAs/AlSb multilayers similar to those used in quantum cascade lasers have been grown by molecular beam epitaxy on (001) InAs substrates. Elastic strain is investigated by high resolution transmission electron microscopy. Thin interfacial regions with lattice distortions significantly different from the strain of the AlSb layers themselves are revealed from the geometrical phase analysis. Strain profiles are qualitatively compared to the chemical contrast of high angle annular dark field images obtained by scanning transmission electron microscopy. The strain and chemical profiles are correlated with the growth sequences used to form the interfaces. Tensile strained AlAs-like interfaces tend to form predominantly due to the high thermal stability of AlAs. Strongly asymmetric interfaces, AlAs-rich and (Al, In)Sb, respectively, can also be achieved by using appropriate growth sequences.
Published: 2016

43. Quantitative 3D electromagnetic field determination of 1D nanostructures from single projection

Author: L. de Knoop, Charudatta Phatak, Florent Houdellier, Martin Hÿtch, Aurélien Masseboeuf, Christophe Gatel, Argonne National Laboratory [Lemont] (ANL), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Electromagnetic field, [PHYS]Physics [physics], Materials science, Field (physics), business.industry, Nanowire, 02 engineering and technology, Carbon nanotube, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, Atomic and Molecular Physics, and Optics, Projection (linear algebra), Electronic, Optical and Magnetic Materials, Magnetic field, law.invention, Optics, Nanoelectronics, law, Electric field, 0103 physical sciences, 010306 general physics, 0210 nano-technology, business, Instrumentation
Abstract: International audience; One-dimensional (1D) nanostructures have been regarded as the most promising building blocks for nanoelectronics and nanocomposite material systems as well as for alternative energy applications. Although they result in confinement of a material, their properties and interactions with other nanostructures are still very much three-dimensional (3D) in nature. In this work, we present a novel method for quantitative determination of the 3D electromagnetic fields in and around 1D nanostructures using a single electron wave phase image, thereby eliminating the cumbersome acquisition of tomographic data. Using symmetry arguments, we have reconstructed the 3D magnetic field of a nickel nanowire as well as the 3D electric field around a carbon nanotube field emitter, from one single projection. The accuracy of quantitative values determined here is shown to be a better fit to the physics at play than the value obtained by conventional analysis. Moreover the 3D reconstructions can then directly be visualized and used in the design of functional 3D architectures built using 1D nanostructures.no abstract
Published: 2016

44. Dynamical holographic Moirés in a TEM

Author: Christophe Gatel, Etienne Snoeck, Florent Houdellier, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: 010302 applied physics, [PHYS]Physics [physics], Materials science, Acoustics and Ultrasonics, business.industry, Resolution (electron density), Holography, 02 engineering and technology, Electron, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, law.invention, Magnetic field, Interferometry, Optics, law, 0103 physical sciences, Microscopy, 0210 nano-technology, business, Carbon nanocone, Excitation
Abstract: International audience; A new electron interferometry method has been developed and implemented in a transmission electron microscope to quantitatively analyse magnetic and electric properties emanating from objects using holograms free of artifacts and with a frequential sensitivity. This method, called dynamical holographic Moirés (DHM), is based on the double-exposure technique consisting in the superimposition of two different holograms. We improved this technique by acquiring the superimposed holograms for two well-defined excitation states of the sample and with a control of the superimposition frequency. The variations of magnetic and electrostatic fields between both excitation states can then be extracted directly from the amplitude part of the so-called interferogram. We demonstrate the efficiency of this method by studying quantitatively the magnetic field generated by a hard disk drive writing head excited by a DC and an AC current. Double exposure measurements have also been performed to study in situ electrostatic properties of a biased carbon nanocone tip. Our method opens the route to dynamical studies using the unique combination of nanoscale resolution and electromagnetic sensitivity of electron interferometry.
Published: 2016

45. Assessment of off-axis and in-line electron holography for measurement of potential variations in Cu(In,Ga)Se2 thin-film solar cells

Author: Christophe Gatel, Etienne Snoeck, Marta D. Rossell, Debora Keller, Rolf Erni, Fabian Pianezzi, Stephan Buecheler, Patrick Reinhard, Ayodhya N. Tiwari, Swiss Federal Laboratories for Materials Science and Technology [Dübendorf] (EMPA), Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)
Subjects: Microscope, Materials science, Mean inner potential (MIP), Holography, Chalcopyrite, In-line, 02 engineering and technology, 01 natural sciences, 7. Clean energy, Electron holography, law.invention, [SPI.MAT]Engineering Sciences [physics]/Materials, Cu(In,Ga)Se2, Optics, law, 0103 physical sciences, Solar cell, Chemical Engineering (miscellaneous), Radiology, Nuclear Medicine and imaging, Spectroscopy, 010302 applied physics, Transport of intensity equation (TIE), business.industry, Resolution (electron density), Cu(In, 021001 nanoscience & nanotechnology, Copper indium gallium selenide solar cells, Characterization (materials science), Off-axis, Grain boundary, 0210 nano-technology, business
Abstract: Electron holography is employed to study variations of the electrostatic crystal potential in Cu(In,Ga)Se2 (CIGS) thin-film solar cells at different length scales: Long-range potential variations across the layer structure of the solar cell as well as inhomogeneities within the layers are analyzed by off-axis holography. In-line holography is applied to examine the local potential variation across a CIGS grain boundary. The phase reconstruction from a focal series is performed by a modified transport of intensity equation (TIE) which is optimized to reduce common artifacts. For comparison, three different microscopes of different optical configurations were used for in-line holography. Based on the results, the impact of the used microscope as well as further acquisition parameters on the in-line holography measurement is assessed. The measured potential variations are discussed considering the effect of different possible sources that may cause potential fluctuations. It is found that most of the variations are best explained by mean inner potential fluctuations rather than by inhomogeneities of the electronic properties. Finally, the present resolution limit of both methods is discussed regarding the feasibility of future electronic characterization of CIGS by holography.
Published: 2016

46. Magnetic Configurations in Co/Cu Multilayered Nanowires: Evidence of Structural and Magnetic Interplay

Author: Christophe Gatel, Nicolas Biziere, T. Wade, Bénédicte Warot-Fonrose, David Reyes, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Matériaux et dispositifs pour l'Electronique et le Magnétisme (CEMES-MEM), Laboratoire des Solides Irradiés (LSI), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), ANR-12-BS10-0013,EMMA,Microscopie Electronique pour le Magnétisme(2012), ANR-12-JS10-0008,NASSICS,Nano-structuration pour la dynamique de spin(2012), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, electron holography, Nanowire, antiparallel coupling, Bioengineering, Nanotechnology, 02 engineering and technology, Micromagnetic, 01 natural sciences, Electron holography, magnetic configuration, vortex state, 0103 physical sciences, General Materials Science, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Saturation (magnetic), micromagnetic simulation, 010302 applied physics, [PHYS]Physics [physics], Condensed matter physics, Nanowires, Mechanical Engineering, Chemical data, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Vortex state, Vortex, electrodeposited, Transmission electron microscopy, nanowire, magnetic materials, 0210 nano-technology, Antiparallel (electronics)
Abstract: International audience; Off-axis electron holography experiments have been combined with micromagnetic simulations to study the remnant magnetic states of electrodeposited Co/Cu multilayered nanocylinders. Structural and chemical data obtained by transmission electron microscopy have been introduced in the simulations. Three different magnetic configurations such as an antiparallel coupling of the Co layers, coupled vortices, and a monodomain-like state have been quantitatively mapped and simulated. While most of the wires present the same remnant state whatever the direction of the saturation field, we show that some layers can present a change from an antiparallel coupling to vortices. Such a configuration can be of particular interest to design nano-oscillators with two different working frequencies.
Published: 2016

47. Enhanced magnetization at the Cr/MgO(001) interface

Author: Stéphane Andrieu, A. Taleb-Ibrahimi, Michael R. Fitzsimmons, A. M. Bataille, Yves Garreau, Christophe Gatel, Qiang Wang, Alessandro Coati, P. Le Fèvre, F. Ott, Adriana Vlad, François Bertran, Thomas Hauet, M. A. Leroy, Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Los Alamos National Laboratory (LANL), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire Matériaux et Phénomènes Quantiques (MPQ (UMR_7162)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Magnetization, Materials science, Physics and Astronomy (miscellaneous), Condensed matter physics, Interface (Java), Photoemission spectroscopy, Antiferromagnetism, Neutron, Spin (physics), Reflectivity
Abstract: WOS:000368442100010; International audience; We report on the magnetization at the Cr/MgO interface, which we studied through two complementary techniques: angle-resolved photoemission spectroscopy and polarized neutron reflectivity. We experimentally observe an enhanced interface magnetization at the interface, yet with values much smaller than the ones reported so far by theoretical and experimental studies on Cr(001) surfaces. Our findings cast some doubts on the interpretations on previous works and could be useful in antiferromagnetic spin torque studies.
Published: 2015

48. Size-Specific Spin Configurations in Single Iron Nanomagnet: From Flower to Exotic Vortices

Author: Thomas Blon, Lise-Marie Lacroix, Anca Meffre, Etienne Snoeck, Bruno Chaudret, Christophe Gatel, Bénédicte Warot-Fonrose, Francisco Javier Bonilla, Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique et chimie des nano-objets (LPCNO), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UPS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)
Subjects: Materials science, electron holography, Condensed matter physics, Mechanical Engineering, Bioengineering, General Chemistry, single domain state, Condensed Matter Physics, Nanomagnet, Vortex state, Electron holography, Vortex, Nuclear magnetic resonance, magnetic configuration, Transmission electron microscopy, vortex state, flower state, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Magnetic nanoparticles, [CHIM]Chemical Sciences, General Materials Science, Spin (physics), nanocube, Phase diagram
Abstract: International audience; The different spin configurations in the vicinity of the single-domain/vortex transition are reported in isolated magnetic nanoparticles. By combining chemical synthesis, electron holography in a dedicated transmission electron microscope and micromagnetic simulations, we establish the “magnetic configurations vs size” phase diagram of Fe single-crystalline nanocubes. Room temperature high resolution magnetic maps reveal the transition between single-domain and vortex states for Fe nanocubes from 25 to 27 nm, respectively. An intermediate spin configuration consisting of an ⟨111⟩ vortex is for the first time evidenced.
Published: 2015

49. Formation of strained interfaces in AlSb/InAs multilayers grown by molecular beam epitaxy for quantum cascade lasers

Author: César Magén, Alexei N. Baranov, Julien Nicolai, Christophe Gatel, Bénédicte Warot-Fonrose, Roland Teissier, Anne Ponchet, Surfaces, Interfaces et Nano-Objets (CEMES-SINanO), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Composants à Nanostructure pour le moyen infrarouge (NANOMIR), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), University of Zaragoza - Universidad de Zaragoza [Zaragoza], ANR-11-BS10-0017,NAIADE,Nanocaractérisation et modélisation d'Antimoniures d'éléments III : Interfaces et Analyse des Déformations d'Epitaxie(2011), European Project: 312483, Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010302 applied physics, business.industry, Resolution (electron density), Analytical chemistry, General Physics and Astronomy, 02 engineering and technology, 021001 nanoscience & nanotechnology, Epitaxy, 01 natural sciences, law.invention, [SPI.TRON]Engineering Sciences [physics]/Electronics, PACS numbers: 68.60.Bs , 68.37.Lp , 68.35.Ct , 68.65.Fg, Annular dark-field imaging, Transmission electron microscopy, law, 0103 physical sciences, Microscopy, Optoelectronics, numbers: 6860Bs, Thermal stability, Electron microscope, 0210 nano-technology, business, PACS: 68.60.Bs , 68.37.Lp , 68.35.Ct , 68.65.Fg, Molecular beam epitaxy
Abstract: International audience; Structural and chemical properties of InAs/AlSb interfaces have been studied by transmission electron microscopy. InAs/AlSb multilayers were grown by molecular beam epitaxy with different growth sequences at interfaces. The out-of-plane strain, determined using high resolution microscopy and geometrical phase analysis, has been related to the chemical composition of the interfaces analyzed by High Angle Annular Dark Field imaging. Considering the local strain and chemistry, we estimated the interface composition and discussed the mechanisms of interface formation for the different growth sequences. In particular, we found that the formation of the tensile AlAs-type interface is spontaneously favored due to its high thermal stability compared to the InSb-type interface. We also showed that the interface composition could be tuned using an appropriate growth sequence.
Published: 2015

50. Off-Axis Electron Holography for the Quantitative Study of Magnetic Properties of Nanostructures: From the Single Nanomagnet to the Complex Device

Author: Mark Anthony Gubbins, Christophe Gatel, M. A. Bashir, Thomas Blon, Aurélien Masseboeuf, F. Bonnilla, Joshua F. Einsle, Etienne Snoeck, Robert M. Bowman, Anca Meffre, Lise-Marie Lacroix, Interférométrie, In situ et Instrumentation pour la Microscopie Electronique (CEMES-I3EM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Laboratoire de physique et chimie des nano-objets (LPCNO), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC), Centre for Nanostructured Media, International Research Centre for Experimental Physics, Queen's University [Belfast] (QUB), Seagate Technology, Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], Nanostructure, Materials science, Nanotechnology, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, Nanomagnet, Electron holography, 0104 chemical sciences, 0210 nano-technology, Instrumentation, ComputingMilieux_MISCELLANEOUS
Abstract: Electron holography (EH) is a powerful interferometric TEM method particularly efficient for the quantitative studies of local electrostatic and magnetic fields at the nanoscale over a field of view as large as few microns. We applied this method to study the magnetic properties of two very different systems: single 20 nm Fe nanocubes and a hard-disk drive writer in operando.
Published: 2015

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