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1. Mass sensing for the advanced fabrication of nanomechanical resonators

Author

Gruber, G., Urgell, C., Tavernarakis, A., Stavrinadis, A., Tepsic, S., Magen, C., Sangiao, S., de Teresa, J. M., Verlot, P., and Bachtold, A.

Subjects
Physics - Applied Physics, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We report on a nanomechanical engineering method to monitor matter growth in real time via e-beam electromechanical coupling. This method relies on the exceptional mass sensing capabilities of nanomechanical resonators. Focused electron beam induced deposition (FEBID) is employed to selectively grow platinum particles at the free end of singly clamped nanotube cantilevers. The electron beam has two functions: it allows both to grow material on the nanotube and to track in real time the deposited mass by probing the noise-driven mechanical resonance of the nanotube. On the one hand, this detection method is highly effective as it can resolve mass deposition with a resolution in the zeptogram range; on the other hand, this method is simple to use and readily available to a wide range of potential users, since it can be operated in existing commercial FEBID systems without making any modification. The presented method allows to engineer hybrid nanomechanical resonators with precisely tailored functionality. It also appears as a new tool for studying growth dynamics of ultra-thin nanostructures, opening new opportunities for investigating so far out-of-reach physics of FEBID and related methods., Comment: Published in Nano Letters

Published
2021
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2. Interrelation of elasticity and thermal bath in nanotube cantilevers

Author

Tepsic, S., Gruber, G., Moller, C. B., Magen, C., Belardinelli, P., Hernadez, E. R., Alijani, F., Verlot, P., and Bachtold, A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We report the first study on the thermal behaviour of the stiffness of individual carbon nanotubes, which is achieved by measuring the resonance frequency of their fundamental mechanical bending modes. We observe a reduction of the Young's modulus over a large temperature range with a slope $-(173\pm 65)$ ppm/K in its relative shift. These findings are reproduced by two different theoretical models based on the thermal dynamics of the lattice. These results reveal how the measured fundamental bending modes depend on the phonons in the nanotube via the Young's modulus. An alternative description based on the coupling between the measured mechanical modes and the phonon thermal bath in the Akhiezer limit is discussed.

Published
2021
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3. Nanowire magnetic force sensors fabricated by focused electron beam induced deposition

Author

Mattiat, H., Rossi, N., Gross, B., Pablo-Navarro, J., Magén, C., Badea, R., Berezovsky, J., De Teresa, J. M., and Poggio, M.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Applied Physics
Abstract

We demonstrate the use of individual magnetic nanowires (NWs), grown by focused electron beam induced deposition (FEBID), as scanning magnetic force sensors. Measurements of their mechanical susceptibility, thermal motion, and magnetic response show that the NWs posses high-quality flexural mechanical modes and a strong remanent magnetization pointing along their long axis. Together, these properties make the NWs excellent sensors of weak magnetic field patterns, as confirmed by calibration measurements on a micron-sized current-carrying wire and magnetic scanning probe images of a permalloy disk. The flexibility of FEBID in terms of the composition, geometry, and growth location of the resulting NWs, makes it ideal for fabricating scanning probes specifically designed for imaging subtle patterns of magnetization or current density., Comment: Main text: 22 pages, 4 figures; Supplementary information: 8 pages, 6 figures

Published
2019
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7. Oxygen vacancies in strained SrTiO$_{3}$ thin films: formation enthalpy and manipulation

Author

Iglesias, L., Sarantopoulos, A., Magen, C., and Rivadulla, F.

Subjects
Condensed Matter - Materials Science
Abstract

We report the enthalpy of oxygen vacancy formation in thin films of electron-doped SrTiO$_{3}$, under different degrees of epitaxial stress. We demonstrate that both compressive and tensile strain decrease this energy at a very similar rate, and promote the formation of stable doubly ionized oxygen vacancies. Moreover, we also show that unintentional cationic vacancies introduced under typical growth conditions, produce a characteristic rotation pattern of TiO$_6$ octahedra. The local concentration of oxygen vacancies can be modulated by an electric field with an AFM tip, changing not only the local electrical potential, but also producing a non-volatile mechanical response whose sign (up/down) can be reversed by the electric field., Comment: Physical Review B (accepted for publication)

Published
2017
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8. Electron degeneracy and intrinsic magnetic properties of epitaxial Nb:SrTiO$_3$ thin-films controlled by defects

Author

Sarantopoulos, A., Ferreiro-Vila, E., Pardo, V., Magen, C., Aguirre, M. H., and Rivadulla, F.

Subjects
Condensed Matter - Materials Science
Abstract

We report thermoelectric power experiments in e-doped thin films of SrTiO$_3$ (STO) which demonstrate that the electronic band degeneracy can be lifted through defect management during growth. We show that even small amounts of cationic vacancies, combined with epitaxial stress, produce a homogeneous tetragonal distortion of the films, resulting in a Kondo-like resistance upturn at low temperature, large anisotropic magnetoresistance, and non-linear Hall effect. Ab-initio calculations confirm a different occupation of each band depending on the degree of tetragonal distortion. The phenomenology reported in this paper for tetragonally distorted e-doped STO thin films, is similarto that observed in LaAlO$_3$/STO interfaces and magnetic STO quantum wells., Comment: 5 pages, 5 figures

Published
2015
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9. Origin of inverse Rashba-Edelstein effect at Cu/Bi interface using lateral spin valves

Author

Isasa, M., Martínez-Velarte, M. C., Villamor, E., Magén, C., Morellón, L., De Teresa, J. M., Ibarra, M. R., Vignale, G., Chulkov, E. V., Krasovskii, E. E., Hueso, L. E., and Casanova, F.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

The spin transport and spin-to-charge current conversion properties of bismuth are investigated using permalloy/copper/bismuth (Py/Cu/Bi)lateral spin valve structures. The spin current is strongly absorbed at the surface of Bi, leading to ultra-short spin diffusion lengths. A spin-to-charge current conversion is measured, which is attributed to the inverse Rashba-Edelstein effect at the Cu/Bi interface. The spin-current-induced charge current is found to change direction with increasing temperature. A theoretical analysis relates this behavior to the complex spin structure and dispersion of the surface states at the Fermi energy. The understanding of this phenomenon opens novel possibilities to exploit spin-orbit coupling to create, manipulate, and detect spin currents in 2D systems., Comment: 10 pages, 4 figures for the main text + 6 pages, 6 figures for the supplementary information

Published
2014
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10. Screening of the quantum-confined Stark effect in AlN/GaN nanowire superlattices by Germanium doping

Author

Hille, P., Müßener, J., Becker, P., de la Mata, M., Rosemann, N., Magén, C., Arbiol, J., Teubert, J., Chatterjee, S., Schörmann, J., and Eickhoff, M.

Subjects
Condensed Matter - Materials Science
Abstract

We report on electrostatic screening of polarization-induced internal electric fields in AlN/GaN nanowire heterostructures with Germanium-doped GaN nanodiscs embedded between AlN barriers. The incorporation of Germanium at concentrations above $10^{20}\,\text{cm}^{-3}$ shifts the photoluminescence emission energy of GaN nanodiscs to higher energies accompanied by a decrease of the photoluminescence decay time. At the same time, the thickness-dependent shift in emission energy is significantly reduced. In spite of the high donor concentration a degradation of the photoluminescence properties is not observed., Comment: Manuscript including Supplemental material (15 pages, 5 figures)

Published
2014
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12. The methane cycle in ferruginous Lake Matano

Author

CROWE, SA, KATSEV, S, LESLIE, K, STURM, A, MAGEN, C, NOMOSATRYO, S, PACK, MA, KESSLER, JD, REEBURGH, WS, ROBERTS, JA, GONZÁLEZ, L, HAFFNER, G DOUGLAS, MUCCI, A, SUNDBY, B, and FOWLE, DA

Subjects
Archaea, Carbon Cycle, Fresh Water, Indonesia, Iron, Manganese, Methane, Molecular Sequence Data, Nitrates, Oxidation-Reduction, Sulfates, Geochemistry, Geology, Ecology, Geochemistry & Geophysics
Abstract

In Lake Matano, Indonesia, the world's largest known ferruginous basin, more than 50% of authigenic organic matter is degraded through methanogenesis, despite high abundances of Fe (hydr)oxides in the lake sediments. Biogenic CH₄ accumulates to high concentrations (up to 1.4 mmol L⁻¹) in the anoxic bottom waters, which contain a total of 7.4 × 10⁵ tons of CH₄. Profiles of dissolved inorganic carbon (ΣCO₂) and carbon isotopes (δ¹³C) show that CH₄ is oxidized in the vicinity of the persistent pycnocline and that some of this CH₄ is likely oxidized anaerobically. The dearth of NO₃⁻ and SO₄²⁻ in Lake Matano waters suggests that anaerobic methane oxidation may be coupled to the reduction of Fe (and/or Mn) (hydr)oxides. Thermodynamic considerations reveal that CH₄ oxidation coupled to Fe(III) or Mn(III/IV) reduction would yield sufficient free energy to support microbial growth at the substrate levels present in Lake Matano. Flux calculations imply that Fe and Mn must be recycled several times directly within the water column to balance the upward flux of CH₄. 16S gene cloning identified methanogens in the anoxic water column, and these methanogens belong to groups capable of both acetoclastic and hydrogenotrophic methanogenesis. We find that methane is important in C cycling, even in this very Fe-rich environment. Such Fe-rich environments are rare on Earth today, but they are analogous to conditions in the ferruginous oceans thought to prevail during much of the Archean Eon. By analogy, methanogens and methanotrophs could have formed an important part of the Archean Ocean ecosystem.

Published
2011

18. Artificial chemical and magnetic structure at the domain walls of an epitaxial oxide

Author

Farokhipoor, S., Magen, C., Venkatesan, S., Iniguez, J., Daumont, C. J. M., Rubi, D., Snoeck, E., Mostovoy, M., de Graaf, C., Muller, A., Doblinger, M., Scheu, C., and Noheda, B.

Subjects
Perovskite -- Magnetic properties -- Analysis, Magnetic susceptibility -- Analysis, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Author(s): S. Farokhipoor [1]; C. Magen (corresponding author) [2, 3]; S. Venkatesan [4]; J. Iniguez [5]; C. J. M. Daumont [1]; D. Rubi [1]; E. Snoeck [3, 6]; M. Mostovoy [...]

Published
2014
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23. Poster: Electronic Structure, Lattice Dynamics, and Transport

Author

Richter, Christoph, primary, Boschker, Hans, additional, Dietsche, Werner, additional, Mannhart, Jochen, additional, Brasse, M., additional, Jany, R., additional, Heyn, Ch., additional, Mannhart, J., additional, Wilde, M. A., additional, Grundler, D., additional, Tada, Masahiro, additional, Miyauchi, Yohei, additional, Yoshiya, Masato, additional, Yasuda, Hideyuki, additional, Sagarna, Leyre, additional, Maegli, Alexandra, additional, Yoon, Songhak, additional, Populoh, Sascha, additional, Shkabko, Andrey, additional, Weidenkaff, Anke, additional, Karthäuser, Silvia, additional, Manheller, Marcel, additional, Waser, Rainer, additional, Blech, Kerstin, additional, Simon, Ulrich, additional, Pengpan, T., additional, Boonthummo, A., additional, Togo, Atsushi, additional, Chaput, Laurent, additional, Tanaka, Isao, additional, Ramírez, M. A, additional, Simões, A. Z, additional, Longo, E., additional, Varela, J. A, additional, Xu, Pengxiang, additional, Schena, Timo, additional, Bihlmayer, Gustav, additional, Blügel, Stefan, additional, Thatribud, A., additional, Tungsurat, T., additional, Tan, X. L., additional, Chen, P. F., additional, Wang, L. F., additional, Zhi, B. W., additional, Wu, W. B., additional, Nikolaev, A. V., additional, Michel, K. H., additional, Tsvyashchenko, A. V., additional, Velichkov, A. I., additional, Salamatin, A. V., additional, Fomicheva, L. N., additional, Ryasny, G. K., additional, Sorokin, A. A., additional, Kochetov, O. I., additional, Budzynski, M., additional, Prieto, P., additional, Gómez, M. E., additional, Puig, T., additional, Obradors, X., additional, Palau, A., additional, Llordés, A., additional, Coll, M., additional, Vlad, R., additional, Gazquez, J., additional, Arbiol, J., additional, Guzmán, R., additional, Pomar, A., additional, Sandiumenge, F., additional, Ricart, S., additional, Rouco, V., additional, Ye, S., additional, Deutscher, G., additional, Chataigner, D., additional, Varela, M., additional, Magen, C., additional, Vanacken, J., additional, Gutierrez, J., additional, Moshchalkov, V. V., additional, Broglia, Giulia, additional, Montorsi, Monia, additional, Larcher, Luca, additional, Padovani, Andrea, additional, Nasr Esfahani, D., additional, Covaci, L., additional, Peeters, F. M., additional, Ohnishi, Hiromasa, additional, Kosugi, Taichi, additional, Miyake, Takashi, additional, Ishibashi, Shoji, additional, Terakura, Kiyoyuki, additional, Medarde, Marisa, additional, Straessle, Thierry, additional, Pomjakushin, Vladimir, additional, Martínez-Lope, María Jesus, additional, Alonso, José Antonio, additional, Nowak, R., additional, Chrobak, D., additional, Gerberich, W. W., additional, Niihara, K., additional, Wyrobek, T., additional, Estradé, S., additional, Rebled, J. M., additional, Walls, M. G., additional, de la Peña, F., additional, Colliex, C., additional, Córdoba, R., additional, Infante, I. C., additional, Herranz, G., additional, Sánchez, F., additional, Fontcuberta, J., additional, Peiró, F., additional, Velessiotis, D., additional, Douvas, A. M., additional, Dimitrakis, P., additional, Argitis, P., additional, Glezos, N., additional, Chrobak, Dariusz, additional, Gerberich, William W., additional, Nowak, Roman, additional, Meyer, Carola, additional, Spudat, C., additional, Müller, M., additional, Houben, L., additional, Maultzsch, J., additional, Goss, K., additional, Thomsen, C., additional, Schneider, C. M., additional, Reza Golobostanfard, Mohammad, additional, Abdizadeh, Hossein, additional, Schmidt, Manuel J., additional, Engels, Stephan, additional, Epping, Alexander, additional, Trellenkamp, Stefan, additional, Wichmann, Uwe, additional, Stampfer, Christoph, additional, Rocha, Paulo R. F., additional, Chen, Qian, additional, Kiazadeh, Asal, additional, Gomes, Henrique L., additional, Meskers, Stefan, additional, de Leeuw, Dago, additional, Paßens, Michael, additional, Busiakiewicz, Adam, additional, Franz, Adam W., additional, Barkschat, Christa S., additional, Urselmann, Dominik, additional, Müller, Thomas J. J., additional, Soltow, A., additional, Karthäuser, S., additional, Waser, R., additional, Zeng, Fei, additional, Yang, Jing, additional, Wang, Zhishun, additional, Lin, Yisong, additional, Li, Sizhao, additional, Hirschfeld, Julian A., additional, and Lustfeld, Hans, additional

Published
2013
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29. POUR QUELLE RÉDUCTION DES RISQUES EN AFRIQUE ET AILLEURS ? PROGRAMME HUMANITAIRE & DÉVELOPPEMENT OBSERVATOIRE DE LA SANTÉ MONDIALE -GLOBAL HEALTH

Author

Magen, C, Dupuis, Christine, Sciences Economiques et Sociales de la Santé & Traitement de l'Information Médicale (SESSTIM - U1252 INSERM - Aix Marseille Univ - UMR 259 IRD), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)

Subjects
[SDV] Life Sciences [q-bio], [SDV.SPEE] Life Sciences [q-bio]/Santé publique et épidémiologie, [SDV]Life Sciences [q-bio], [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie
Abstract

Programme Humanitaire & Développement

Published
2019

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

Author

Nicolaï, J., Warot-Fonrose, B., Gatel, C., Teissier, R., Baranov, A. N., Magen, C., and Ponchet, A.

Subjects
COMBINATORIAL geometry, METALLIC epitaxial layers, CHEMICAL reactions, MOLECULAR beam epitaxy, THERMAL oxidation (Materials science), INTERFACES (Physical sciences)
Abstract

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. [ABSTRACT FROM AUTHOR]

Published
2015
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32. [Fe.sub.3][O.sub.4]/MgO/Fe heteroepitaxial structures for magnetic tunnel junctions

Author

Orna, J., Morellon, L., Algarabel, P.A., Pardo, J.A., Sangiao, S., Magen, C., Snoeck, E., De Teresa, J.M., and Ibarra, M.R.

Subjects
Chemical compounds -- Magnetic properties, Epitaxy -- Analysis, Ablation (Vaporization technology) -- Analysis, Magnetic materials -- Magnetic properties, Business, Electronics, Electronics and electrical industries
Abstract

In this work we report the growth and structural and magnetic characterization of heteroepitaxial [Fe.sub.3][O.sub.4]/MgO/Fe junctions. All three layers have been deposited by pulsed laser deposition. Combining High Resolution Transmission Electron Microscopy and X-ray results, we have obtained for the heterostructure the epitaxy relation MgO(001) [100]//[Fe.sub.3][O.sub.4] (001)[100]/MgO(001)[100]/Fe(001)[110]. All interfaces appear very sharp with relatively small root-mean square (rms) roughness, ~ 0.2 nm. The magnetic coupling between [Fe.sub.3][O.sub.4] and Fe electrodes is also very small, J ~ 0.03 mJ/[m.sup.2] (MgO barrier thickness of 2 nm). Microfabrication of Magnetic Tunnel Junctions from these heterostructures is in progress. Index Terms--Epitaxial layers, pulsed laser deposition, spintronics, thin films.

Published
2008

33. Epitaxial La0.7Sr0.3MnO3 thin films on silicon with excellent magnetic and electric properties by combining physical and chemical methods

Author

Vila-Fungueirino, J.M., Gazquez, J., Magen, C., Saint-Girons, G., Bachelet, R., Carretero-Genevrier, A., Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Matériaux, MicroCapteurs et Acoustique (M2A), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Fundación ARAID, INL - Hétéroepitaxie et Nanostructures (INL - H&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Agence Nationale de la Recherche (France), Ecole Normale Supérieure de Lyon, European Commission, Vila-Fungueiriño, José M. [0000-0002-1839-0495], Magen, Cesar [0000-0002-6761-6171], Bachelet, Romain [0000-0002-2910-0449], Carretero Genevrier, Adrian [0000-0003-0488-9452], Vila-Fungueiriño, José M., Magen, Cesar, Bachelet, Romain, and Carretero Genevrier, Adrian

Subjects
lcsh:Biotechnology, Thin-films, [CHIM.MATE]Chemical Sciences/Material chemistry, Chemical solution deposition, chemical solution deposition, Functional oxides, molecular beam epitaxy, lcsh:TP248.13-248.65, functional oxides, silicon integration, lcsh:TA401-492, lcsh:Materials of engineering and construction. Mechanics of materials, Silicon integration, Molecular beam epitaxy
Abstract

Half-metallic ferromagnetic La0.7Sr0.3MnO3 (LSMO) represents an appealing candidate to be integrated on silicon substrates for technological devices such as sensors, data storage media, IR detectors, and so on. Here, we report high-quality epitaxial LSMO thin films obtained by an original combination of chemical solution deposition (CSD) and molecular beam epitaxy (MBE). A detailed study of the thermal, chemical, and physical compatibility between SrTiO3 (STO)/Si buffer layers and LSMO films, grown by MBE and CSD, respectively, enables a perfect integration of both materials. Importantly, we show a precise control of the coercive field of LSMO films by tuning the mosaicity of the STO/Si buffer layer. These results demonstrate the enormous potential of combining physical and chemical processes for the development of low-cost functional oxide-based devices compatible with the complementary metal oxide semiconductor technology., ACG acknowledges the financial support from the French Agence Nationale pour la Recherche (ANR), project Q-NOSS ANR-16-CE09-0006-01 and École Centrale de Lyon under the BQR 2016 project. The research leading to these results has received funding from the European Union Seventh Framework Program under Grant Agreement 312483 - ESTEEM2 (Integrated Infrastructure Initiative–I3). This project has received funding from the EU‐H2020 research and innovation Program under grant agreement No 654360 having benefitted from the access provided by ICMAB-CSIC in Barcelona within the framework of the NFFA‐Europe Transnational Access Activity. Fruitful discussions with Pr. F. Rivadulla from USC are highly acknowledged. INL authors acknowledge the European Commission for funding the project TIPS (H2020-ICT-02-2014-1-644453). We thank P. Regreny, C. Botella, and J. B. Goure for the MBE technical assistance on the Nanolyon technological platform.

Published
2018

34. Epitaxial integration of nanostructured functional oxides on silicon by solution chemistry

Author

Vila-Fungueiriño, José M., Andrés, Gómez, Saint-Girons, Guillaume, Magen, C., Gazquez, Jaume, Bachelet, Romain, Gich, M., Rivadulla, Francisco, Carretero-Genevrier, Adrian, Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Matériaux, MicroCapteurs et Acoustique (M2A), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), INL - Hétéroepitaxie et Nanostructures (INL - H&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Universidad de Zaragossa, Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE), and Saint-Girons, Guillaume

Subjects
[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

35. Emerging Diluted Ferromagnetism in High-T-c Superconductors Driven by Point Defect Clusters

Author

Gazquez, J., Guzman, R., Mishra, R., Bartolome, E., Salafranca, J., Magen, C., Varela, M., Coll, M., Palau, A., Valvidares, S.M., Gargiani, P., Pellegrin, E., Herrero-Martin, J., Pennycook, S.J., Pantelides, S.T., Puig, T., and Obradors, X.

Subjects
Condensed Matter::Superconductivity
Abstract

Defects in ceramic materials are generally seen as detrimental to their functionality and applicability. Yet, in some complex oxides, defects present an opportunity to enhance some of their properties or even lead to the discovery of exciting physics, particularly in the presence of strong correlations. A paradigmatic case is the high-temperature superconductor YBa2Cu3O7-delta(Y123), in which nanoscale defects play an important role as they can immobilize quantized magnetic flux vortices. Here previously unforeseen point defects buried in Y123 thin films that lead to the formation of ferromagnetic clusters embedded within the superconductor are unveiled. Aberration-corrected scanning transmission microscopy has been used for exploring, on a single unit-cell level, the structure and chemistry resulting from these complex point defects, along with density functional theory calculations, for providing new insights about their nature including an unexpected defect-driven ferromagnetism, and X-ray magnetic circular dichroism for bearing evidence of Cu magnetic moments that align ferromagnetically even below the superconducting critical temperature to form a dilute system of magnetic clusters associated with the point defects.

Published
2018

36. Role of magnetic anisotropy on the magnetic properties of Ni nanoclusters embedded in a ZnO matrix.

Author

Nunes, W. C., Borges, R. P., Cruz, M. M., da Silva, R. C., Wahl, U., Cuchillo, A., Vargas, P., Magen, C., and Godinho, M.

Subjects
MAGNETIC anisotropy, ZINC oxide, SINGLE crystals, ANTIFERROMAGNETISM, MAGNETIC nanoparticles, MAGNETIC recording media
Abstract

We have investigated the magnetic properties of Ni nanoaggregates produced by ion implantation in ZnO single crystals. Several deviations from classical models usually adopted to describe the magnetic properties of nanoparticle systems were found. The strain between host and Ni nanoaggregates induces a magnetic anisotropy with a preferred direction. We show that these anisotropy effects can be misinterpreted as a ferromagnetic or antiferromagnetic coupling among the nanoaggregates similar to that of an oriented, interacting nanocrystal ensemble. [ABSTRACT FROM AUTHOR]

Published
2014
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38. Epitaxial growth of nanostructured functional oxides on silicon by solution chemistry

Author

Vila-Fungueiriño, José M., Gomez, A., Moalla, R., Saint-Girons, Guillaume, Magen, C., Gazquez, Jaume, Bachelet, Romain, GICH, M., RIVADULLA, F., Carretero-Genevrier, Adrian, Institut d’Electronique et des Systèmes (IES), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Matériaux, MicroCapteurs et Acoustique (M2A), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), INL - Hétéroepitaxie et Nanostructures (INL - H&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Saint-Girons, Guillaume, Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-École Centrale de Lyon (ECL), Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)

Subjects
[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.COND.CM-MS] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2017

39. Tuning shape, composition and magnetization of three-dimensional cobalt nanowires grown by Focused Electron Beam Induced Deposition (FEBID)

Author

PABLO-NAVARRO, JAVIER, SANZ-HERNANDEZ, DEDALO, Magen, C, Fernandez-Pacheco, A, de Teresa, JM, Fernandez-Pacheco, Amalio [0000-0002-3862-8472], and Apollo - University of Cambridge Repository

Subjects
electron holography, cobalt nanowires, focused electron beam induced deposition, magnetic nanowires
Abstract

Electron beam induced deposition of 3D cobalt nanowires with simultaneous high metallic content (≈80% at.) and small diameter (

Published
2017
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40. Effect of metallic buffer layers on the antiphase boundary density of epitaxial Fe3O4.

Author

Magen, C., Snoeck, E., Lüders, U., and Bobo, J. F.

Subjects
*EPITAXY, *IRON oxides, *MAGNETITE, *MAGNETIZATION, *MAGNETIC fields, *THIN films, *HYSTERESIS loop, *MAGNETIC properties
Abstract

We report a strong variation of the magnetic properties and of the antiphase boundaries (APBs) density of Fe3O4(001) epitaxial thin films grown on thin Fe(001) and Cr(001) buffer layers on a MgO(001) substrate in comparison with similar magnetite films grown directly on MgO(001). The magnetization of the Fe/Fe3O4 and Cr/Fe3O4 bilayers presents a more squared hysteresis loop and reach saturation at much lower magnetic field (∼10–15 kOe) than the Fe3O4 thin films of same thickness, which hardly saturate at 70 kOe. The magnetization of the magnetite layers has been estimated on both the Fe- and Cr-based samples and a value close to that of the bulk Fe3O4 has been obtained, which points to the magnetic saturation of the Fe3O4 layer induced by the metallic buffers. Transmission electron microscopy has been used to investigate the possible structural origin of this phenomenon studying the APB network of Fe3O4 in the three types of samples. The calculation of the average domain size reveals that the APB density in the bilayers is substantially reduced in comparison with their counterparts without buffer. The domain sizes obtained in Fe and Cr samples are similar, which points to a structural origin probably due to the strain caused by the lattice misfit between the buffers and the magnetite. A lower APB density statistically reduces the influence of the antiferromagnetic interactions existing across some of the boundaries, achieving the saturation of the Fe3O4 layer at much lower magnetic fields. [ABSTRACT FROM AUTHOR]

Published
2008
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41. Effect of metallic buffer layers on the antiphase boundary density of epitaxial Fe3O4.

Author

Magen, C., Snoeck, E., Lüders, U., and Bobo, J. F.

Subjects
EPITAXY, IRON oxides, MAGNETITE, MAGNETIZATION, MAGNETIC fields, THIN films, HYSTERESIS loop, MAGNETIC properties
Abstract

We report a strong variation of the magnetic properties and of the antiphase boundaries (APBs) density of Fe3O4(001) epitaxial thin films grown on thin Fe(001) and Cr(001) buffer layers on a MgO(001) substrate in comparison with similar magnetite films grown directly on MgO(001). The magnetization of the Fe/Fe3O4 and Cr/Fe3O4 bilayers presents a more squared hysteresis loop and reach saturation at much lower magnetic field (∼10–15 kOe) than the Fe3O4 thin films of same thickness, which hardly saturate at 70 kOe. The magnetization of the magnetite layers has been estimated on both the Fe- and Cr-based samples and a value close to that of the bulk Fe3O4 has been obtained, which points to the magnetic saturation of the Fe3O4 layer induced by the metallic buffers. Transmission electron microscopy has been used to investigate the possible structural origin of this phenomenon studying the APB network of Fe3O4 in the three types of samples. The calculation of the average domain size reveals that the APB density in the bilayers is substantially reduced in comparison with their counterparts without buffer. The domain sizes obtained in Fe and Cr samples are similar, which points to a structural origin probably due to the strain caused by the lattice misfit between the buffers and the magnetite. A lower APB density statistically reduces the influence of the antiferromagnetic interactions existing across some of the boundaries, achieving the saturation of the Fe3O4 layer at much lower magnetic fields. [ABSTRACT FROM AUTHOR]

Published
2008
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42. Magnetic anisotropy of epitaxial Co2Fe-Ge Heusler alloy films on MgO (100) substrates

Author

Pogorily, A. N., Kravets, Anatolii, Nevdacha, V. V., Podyalovskiy, D. Y., Ryabchenko, S. M., Kalita, V. M., Kulik, M. M., Lozenko, A. F., Vovk, A.Ya., Godinho, M., Maurel, L., Pardo, J. A., Magen, C., Korenivski, V., Pogorily, A. N., Kravets, Anatolii, Nevdacha, V. V., Podyalovskiy, D. Y., Ryabchenko, S. M., Kalita, V. M., Kulik, M. M., Lozenko, A. F., Vovk, A.Ya., Godinho, M., Maurel, L., Pardo, J. A., Magen, C., and Korenivski, V.

Abstract

Films of Co2Fe-Ge Heusler alloy with variable Ge concentration deposited on monocrystalline MgO (100) substrates by magnetron co-sputtering are investigated using microstructural, morphological, magnetometric, and magnetic resonance methods. The films were found to grow epitaxially, with island-like or continuous-layer morphology depending the Ge-content. The ferromagnetic resonance data versus out-of-plane and in-plane angle indicate the presence of easy plane and 4-fold in-plane anisotropy. The magnetometry data indicate additional weak 2-fold in-plane anisotropy and pronounced at low fields rotatable anisotropy. The observed magnetic anisotropy properties discussed in correlation with the microstructure and morphology of the films., QC 20170607

Published
2017
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43. Insights on the origin of the Tb5Ge4 magnetocaloric effect

Author

Belo, J., Barbosa, M., Pires, A., Costa, R., Teixeira, J., Silva, J., Algarabel, P., Magen, C., Morellon, L., Amaral, J., Zeitler, U., Veerendra, G., dos Santos, A.M., Ren, Y, Ibarra, M.R., Pereira, A.M., Belo, J., Barbosa, M., Pires, A., Costa, R., Teixeira, J., Silva, J., Algarabel, P., Magen, C., Morellon, L., Amaral, J., Zeitler, U., Veerendra, G., dos Santos, A.M., Ren, Y, Ibarra, M.R., and Pereira, A.M.

Abstract

Item does not contain fulltext

Published
2017

44. Morphology and magnetic properties of W-capped Co nanoparticles

Author

Figueroa, A.I., Bartolome, J., Garcia, L.M., Bartolome, F., Magen, C., Ibarra, A., Ruiz, L., Gonzalez-Calbet, J.M., Petroff, F., and Deranlot, C.

Subjects
Cobalt -- Magnetic properties, Cobalt -- Electric properties, Scanning microscopy -- Usage, Superconducting quantum interference devices -- Design and construction, Tungsten alloys -- Magnetic properties, Tungsten alloys -- Electric properties, Physics
Abstract

The high resolution and scanning transmission electron microscopy techniques are employed to explain the preparation, morphology and the magnetic properties of the various W-capped Co nanoparticles. A increase in the nominal thickness of the W capping layer is shown to lead to a reduction in the formation of the Co-E alloys.

Published
2010

45. Tunneling magnetoresistance in Fe/MgO granular multilayers

Author

Garcia-Garcia, A., Vovk, A., Pardo, J.A., Strichovanec, P., Algarabel, P.A., Magen, C., De Teresa, J.M., Morellon, L., and Ibarra, M.R.

Subjects
Magnesium oxide -- Magnetic properties, Magnesium oxide -- Electric properties, Magnetoresistance -- Analysis, Tunneling (Physics) -- Analysis, Iron -- Electric properties, Iron -- Magnetic properties, Physics
Abstract

The transport and magnetotransport properties in Fe/MgO multilayers around the Fe percolation threshold are explored as a function of the temperature and the nominal thickness of iron layer (t). The samples with Fe thickness below percolation threshold are explained by considering spin-polarized electron tunneling between nanometer-sized, superparamagnetic Fe grains.

Published
2010

46. Structural and magnetic properties of He + irradiated Co 2 MnSi Heusler alloys

Author

Abdallah , I., Ratel-Ramond , Nicolas, Magen , C., Pécassou , Béatrice, Cours , C, Arnoult , A, Respaud , Marc, Bobo , Jean-François, BenAssayag , Gérard, Snoeck , Etienne, Biziere , N., 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 ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Toulouse III - Paul Sabatier ( UPS ), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Laboratorio de microscopias avanzadas ( LMA ), Universidad de Zaragoza, Laboratoire d'analyse et d'architecture des systèmes [Toulouse] ( LAAS ), 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 ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Institut National Polytechnique [Toulouse] ( INP ), Laboratoire de physique et chimie des nano-objets ( LPCNO ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Université Toulouse III - Paul Sabatier ( UPS ), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique ( CNRS )

Subjects
[ PHYS.PHYS.PHYS-CHEM-PH ] Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]
Abstract

International audience; We have investigated the atomic disorder induced by a 150 keV He+ ion irradiation in a 40 nm thick Co2MnSi Heusler alloy. Disorder parameters on each atomic site are deduced from normal and anomalous x-ray diffraction measurements with Co and Cu Kα sources. While the film grows mainly in the L21 phase with inclusion of B2 grains, we observe an increase of both the Mn–Si and Co–Mn exchanges with the ion fluence. HAADF-STEM analysis demonstrates that the increase in Mn–Si disorder corresponds to a growing size of the B2 grains while the Co–Mn exchange is accounted for a D03 disorder type in the L21 matrix. These structural modifications are shown to decrease the average magnetization of the alloy, which is due to D03 disorder and local defects induced by irradiation.

Published
2016

47. Magnetic properties of Fe/MgO granular multilayers prepared by pulsed laser deposition

Author

Garcia-Garcia, A., Vovk, A., Pardo, J.A., Strichovanec, P., Magen, C., Snoeck, E., Algarabel, P.A., De Teresa, J.M., Morellon, L., and Ibarra, M.R.

Subjects
Iron alloys -- Magnetic properties, Iron alloys -- Structure, Ablation (Vaporization technology) -- Usage, Magnesium oxide -- Magnetic properties, Magnesium oxide -- Structure, Magnetization -- Analysis, Physics
Abstract

Granular multilayers Fe/MgO are prepared by sequential pulsed laser deposition and the magnetic properties are examined. The reduction of saturation magnetization for Fe nanoparticles and an increase of the coercivity at low temperatures are attributed to the formation of Fe-core/Fe[O.sub.x]-shell structured nanocrystals.

Published
2009

48. Strain and Cation Stoichiometry in Epitaxial BaTiO3 Thin Films Grown on Silicon

Author

Schamm-Chardon, Sylvie, Magen, C., Guzman, R., MAZET, Lucie, Cours, Robin, Bachelet, Romain, Saint-Girons, Guillaume, Hÿtch , Martin, Dubourdieu, Catherine, 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), University of Zaragoza - Universidad de Zaragoza [Zaragoza], INL - Hétéroepitaxie et Nanostructures (INL - H&N), Institut des Nanotechnologies de Lyon (INL), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-École Supérieure de Chimie Physique Électronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), Université de Lyon-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-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 Lyon-École supérieure de Chimie Physique Electronique de Lyon (CPE)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Lyon (ECL), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2015

49. Effect of metallic buffer layers on the antiphase boundary density of epitaxial [Fe.sub.3][O.sub.4]

Author

Magen, C., Snoeck, E., Luders, U., and Bobo, J.F.

Subjects
Iron oxides -- Magnetic properties, Iron oxides -- Electric properties, Magnetization -- Research, Buffers (Chemistry) -- Research, Dibromopropanol phosphate -- Research, Physics
Abstract

The magnetization and transmission electron microscopy (TEM) is used for studying the magnetic properties and the antiphase boundaries (APBs) density of [Fe.sub.3][O.sub.4] thin films grown on different magnetic buffer layers with a large lattice misfit and different magnetic structures such as Fe and Cr. It is shown that a lower APB density has reduced the effect of the antiferromagnetic interactions existing across some of the boundaries, which has achieved the saturation of the [Fe.sub.3][O.sub.4] layer at much lower magnetic fields.

Published
2008

50. Probing Strain-Induced Phenomena in Low Dimensionality Multiferroic Oxides

Author

Magen, C., primary, Guzman, R., additional, Farokhipoor, S., additional, Maurel, L., additional, Langenberg, E., additional, Iniguez, J., additional, Venkatesan, S., additional, Lupini, Andrew R., additional, Snoeck, E., additional, Mostovoy, M., additional, Algarabel, P. A., additional, Pardo, J. A., additional, and Noheda, B., additional

Published
2017
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