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13 results on '"Laboratory TASC"'

1. Biaxial strain in the hexagonal plane of MnAs thin films: The key to stabilize ferromagnetism to higher temperature

Author

F. Maccherozzi, Frédéric Ott, P. Bourges, Massimiliano Marangolo, Victor H. Etgens, Yvan Sidis, Franck Vidal, Mahmoud Eddrief, Vincent Garcia, G. Panaccione, Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratory TASC, INFM-CNR, Laboratory TASC (TASC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, TASC - Laboratory TASC, 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 ), Laboratory TASC ( TASC ), Institut des Nanosciences de Paris ( INSP ), and Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS )

Subjects
Phase transition, Materials science, General Physics and Astronomy, FOS: Physical sciences, 02 engineering and technology, Substrate (electronics), Neutron scattering, 01 natural sciences, Condensed Matter::Materials Science, MAGNETIC-PROPERTIES, Phase (matter), 0103 physical sciences, Thin film, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, Phase diagram, Condensed Matter - Materials Science, Condensed matter physics, Plane (geometry), GAAS, Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, Ferromagnetism, 0210 nano-technology, [ PHYS.COND ] Physics [physics]/Condensed Matter [cond-mat]
Abstract

The alpha-beta magneto-structural phase transition in MnAs/GaAs(111) epilayers is investigated by elastic neutron scattering. The in-plane parameter of MnAs remains almost constant with temperature from 100 K to 420 K, following the thermal evolution of the GaAs substrate. This induces a temperature dependent biaxial strain that is responsible for an alpha-beta phase coexistence and, more important, for the stabilization of the ferromagnetic alpha-phase at higher temperature than in bulk. We explain the premature appearance of the beta-phase at 275 K and the persistence of the ferromagnetic alpha-phase up to 350 K with thermodynamical arguments based on the MnAs phase diagram. It results that the biaxial strain in the hexagonal plane is the key parameter to extend the ferromagnetic phase well over room temperature., 4 pages, 3 figures, accepted for publication in Physical Review Letters

Published
2007
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2. Temperature-dependent magnetism of Fe thin films on ZnSe(001)

Author

Ezio Puppin, Massimiliano Brenna, Riccardo Bertacco, Franco Ciccacci, M. Eddrieff, Francesco Maccherozzi, Ermanno Pinotti, Matteo Cantoni, Piero Torelli, G. Panaccione, Massimiliano Marangolo, Jun Fujii, Politecnico di Milano [Milan] (POLIMI), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), CNR Istituto Officina dei Materiali, National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), TASC - Laboratory TASC, INFM-CNR, TASC national laboratory, Trieste, Laboratory TASC (TASC), INFM and L-NESS, Dipartimento di Fisica del Politecnico di Milano, Istituto Nazionale di Fisica Nucleare (INFN), and Consiglio Nazionale delle Ricerche (CNR)

Subjects
Materials science, Kerr effect, Condensed matter physics, Magnetic circular dichroism, Magnetism, thin film, 02 engineering and technology, Coercivity, Atmospheric temperature range, 021001 nanoscience & nanotechnology, Condensed Matter Physics, superparamagnetism, 01 natural sciences, blocking temperature, Electronic, Optical and Magnetic Materials, Overlayer, Ferromagnetism, ZnSe, 0103 physical sciences, GROWTH, coercivity, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, Superparamagnetism
Abstract

Joint European Magnetic Symposia (JEMS 06), San Sebastian, SPAIN, JUN 26-29, 2006; International audience; We present X-ray magnetic circular dichroism (XMCD) and magneto-optical Kerr effect (MOKE) data on the magnetic properties of Fe/ZnSe(0 0 1) thin films at increasing Fe coverage. The magnetic behaviour of the Fe overlayer is superparamagnetic for a coverage up to 6 monolayers whereas, above this threshold, a truly ferromagnetic phase shows up. XMCD and MOKE data show that this behaviour is substantially unchanged in the temperature range 10-300K for all the investigated coverages: these findings imply that the blocking temperature is definitely below 10 K. (C) 2007 Elsevier B.V. All rights reserved.

Published
2007
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3. Circular dichroism in photoemission as a fingerprint of surface band structure: The case of ZnSe(001)-c(2x2)

Author

Vidal , Franck, Marangolo , M., Torelli , P., Eddrief , M., Mulazzi , M., Panaccione , G., Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), CNR Istituto Officina dei Materiali, Consiglio Nazionale delle Ricerche (CNR), Laboratory TASC (TASC), INFM-CNR, National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Institut des Nanosciences de Paris ( INSP ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), CNR, Ist Off Mat, and Laboratory TASC ( TASC )

Subjects
MOLECULES, Condensed Matter::Materials Science, PHOTOELECTRON ANGULAR-DISTRIBUTIONS, OPTICAL-ACTIVITY, Condensed Matter::Strongly Correlated Electrons, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], [ PHYS.COND ] Physics [physics]/Condensed Matter [cond-mat], CONTINUOUS ABSORPTION, REGION
Abstract

International audience; Measurements of circular dichroism in the angular dependence (CDAD) of photoemission from core levels and valence bands of the ZnSe(001)-c(2x2) surface are presented. Due to the lowering of the surface symmetry compared to the bulk, the CDAD of surface-related spectral components and of bulk components exhibit different polar variations. We propose a way to identify experimentally surface-related bands in the valence-band photoemission spectra based on these symmetry considerations.

Published
2007
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4. Protected surface state in stepped Fe (0 18 1)

Author

Jun Fujii, Piero Torelli, Fausto Sirotti, Giancarlo Panaccione, Manuel Izquierdo, Giorgio Rossi, Ivana Vobornik, CNR Istituto Officina dei Materiali (IOM), Consiglio Nazionale delle Ricerche [Roma] (CNR), Istituto Officina dei Materiali-CNR (IOM), Laboratory TASC, INFM-CNR, Synchrotron SOLEIL (SSOLEIL), and Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Science, Synchrotron radiation, Angle-resolved photoemission spectroscopy, 02 engineering and technology, Electronic structure, engineering.material, 01 natural sciences, Molecular physics, Article, Overlayer, Electronic states, Coating, 0103 physical sciences, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Multidisciplinary, Spintronics, 021001 nanoscience & nanotechnology, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], engineering, Medicine, 0210 nano-technology, Vicinal
Abstract

Carbon (C) surface segregation from bulk stabilizes the Fe(0 18 1) vicinal surface by forming a c(3$$\sqrt{2}$$ 2 × $$\sqrt{2}$$ 2 reconstruction with C zig-zag chains oriented at 45° with respect to the iron surface steps. The iron surface electronic states as measured by high resolution ARPES at normal emission with polarized synchrotron radiation split in two peaks that follow distinct energy dispersion curves. One peak follows the dispersion of the carbon superstructure and is photoexcited only when the polarization vector is parallel to the steps, the second peak disperses similarly to the pristine Fe(0 0 1) surface. Such surface electronic structure is robust as it persists even after coating with an Ag overlayer. The robustness of this surface electronic structure and its similarity with that of the clean Fe(0 0 1) surface make this system of interest for magnetic and spintronic properties such as magneto tunnel junctions based on Fe/MgO interface.

Published
2017
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5. c-Axis Dimer and Its Electronic Breakup: The Insulator-to-Metal Transition in Ti2O3

Author

Chang C.F., Koethe T.C., Hu Z., Weinen J., Agrestini S., Zhao L., Gegner J., Ott H., Panaccione G., Wu H., Haverkort M.W., Roth H., Komarek A.C., Offi F., Monaco G., Liao Y.-F., Tsuei K.-D., Lin H.-J., Chen C.T., Tanaka A., Tjeng L.H., Max Planck Institute for Chemical Physics of Solids (CPfS), Max-Planck-Gesellschaft, University of Cologne, Laboratory TASC, INFM-CNR, Laboratory for Computational Physical Sciences, Surface Physics Laboratory and Department of Physics, Fudan University, Fudan University [Shanghai], Heidelberg University, Dipartimento di Scienze Fisiche and Unità CNISM, Università degli studi di Napoli Federico II, European Synchrotron Radiation Facility (ESRF), National Synchrotron Radiation Research Center, Department of Quantum Matter/ADSM (ADSM), Hiroshima University, Chang, C. F., Koethe, T. C., Hu, Z., Weinen, J., Agrestini, S., Zhao, L., Gegner, J., Ott, H., Panaccione, G., Wu, Hua, Haverkort, M. W., Roth, H., Komarek, A. C., Offi, F., Monaco, G., Liao, Y. -F., Tsuei, K. -D., Lin, H. -J., Chen, C. T., Tanaka, A., and Tjeng, L. H.

Subjects
[PHYS]Physics [physics], photoemission spectroscopy, SURFACE, Physics, QC1-999, titanium oxide, TI 2P, V2O3, Physics and Astronomy (all), RESONANT 3D, PHOTOEMISSION SPECTRA, VO2, X-RAY-ABSORPTION, metal-insulator transion, Condensed Matter::Strongly Correlated Electrons, CRYSTAL-STRUCTURE, OXIDES, HYBRIDIZATION
Abstract

International audience; We report on our investigation of the electronic structure of Ti2O3 using (hard) x-ray photoelectron and soft x-ray absorption spectroscopy. From the distinct satellite structures in the spectra, we have been able to establish unambiguously that the Ti-Ti c-axis dimer in the corundum crystal structure is electronically present and forms an a(1g)a(1g) molecular singlet in the low-temperature insulating phase. Upon heating, we observe a considerable spectral weight transfer to lower energies with orbital reconstruction. The insulator-metal transition may be viewed as a transition from a solid of isolated Ti-Ti molecules into a solid of electronically partially broken dimers, where the Ti ions acquire additional hopping in the a-b plane via the e(g)(pi) channel, the opening of which requires consideration of the multiplet structure of the on-site Coulomb interaction.

Published
2018
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6. Adsorption of 2-butyne on Si(001) at room temperature: A valence band photoemission study

Author

François Rochet, Jun Fujii, Fabrice Bournel, Giancarlo Panaccione, Jean-Jacques Gallet, Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), TASC national laboratory, Trieste, Laboratory TASC (TASC), and INFM-CNR

Subjects
Silicon, Photoemission spectroscopy, Dimer, Inverse photoemission spectroscopy, chemistry.chemical_element, Angle-resolved photoemission spectroscopy, Molecular physics, chemistry.chemical_compound, SI(100), Atomic orbital, Physics::Atomic and Molecular Clusters, Materials Chemistry, [CHIM]Chemical Sciences, Molecular orbital, Physics::Chemical Physics, SPECTROSCOPY, SURFACES, Surfaces and Interfaces, Condensed Matter Physics, ETHYLENE, Surfaces, Coatings and Films, STATES, chemistry, Condensed Matter::Strongly Correlated Electrons, Atomic physics, Vicinal
Abstract

We present an angle resolved ultraviolet photoemission spectroscopy study of the adsorption of 2-butyne (CH3-C C-CH3) on Si(001)-2 x 1 at room temperature. We recorded valence band photoemission spectra for two azimuthal positions of a vicinal silicon surface, where all the rows formed by the surface silicon dimers are parallel. The photoemission symmetry selection rules allow the determination of the orientation of the molecular orbitals. The photoemission signal of the HOMO is enhanced when the electric field is parallel to the dimer rows. This showed that the pi orbital left intact after the cyclo-addition reaction of the molecule with one silicon dimer is parallel to the dimer rows. This indicates that each 2-butyne molecule adsorbs on one silicon dimer. In spite of the size of the system and the vicinity of the orbitals, the angle resolved study points out that no dispersion of the electronic bands occurs. Not all the surface dimers are reacted so some disorder still exists on the surface preventing the formation of Bloch states. (c) 2007 Elsevier B.V. All rights reserved.

Published
2007
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7. Local electronic structure and photoelectrochemical activity of partial chemically etched Ti-doped hematite

Author

Maxime Rioult, D. Stanescu, Rachid Belkhou, Cindy L. Rountree, Hélène Magnan, Stefan Stanescu, Antoine Barbier, Francesco Maccherozzi, Laboratoire Nano-Magnétisme et Oxydes (LNO), 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, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), TASC - Laboratory TASC, INFM-CNR, Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes (SPHYNX), and This work was funded by the CEA project DSM-Energie Hemaphoto and supported in part by Triangle de la Physique and Ile-de-France (C'Nano and ISC-PIF) under the IMAFMP grants.

Subjects
Materials science, Band gap, Inorganic chemistry, Oxide, 02 engineering and technology, 010402 general chemistry, 7. Clean energy, 01 natural sciences, chemistry.chemical_compound, Materials Chemistry, Absorption (electromagnetic radiation), [PHYS]Physics [physics], Surfaces and Interfaces, Hematite, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 0104 chemical sciences, Surfaces, Coatings and Films, Chemical energy, Chemical engineering, chemistry, visual_art, Photoelectrolysis, visual_art.visual_art_medium, Photocatalysis, Water splitting, 0210 nano-technology
Abstract

International audience; The direct conversion of solar light into chemical energy or fuel through photoelectrochemical water splitting is promising as a clean hydrogen production solution. Ti-doped hematite (Ti:α-Fe 2 O 3) is a potential key photoanode material, which despite its optimal band gap, excellent chemical stability, abundance, non-toxicity and low cost, still has to be improved. Here we give evidence of a drastic improvement of the water splitting performances of Ti-doped hematite photoanodes upon a HCl wet-etching. In addition to the topography investigation by atomic force microscopy, a detailed determination of the local electronic structure has been carried out in order to understand the phenomenon and to provide new insights in the understanding of solar water splitting. Using synchrotron radiation based spectromicroscopy (X-PEEM), we investigated the X-ray absorption spectral features at the L 3 Fe edge of the as grown surface and of the wet-etched surface on the very same sample thanks to patterning. We show that HCl wet etching leads to substantial surface modifications of the oxide layer including increased roughness and chemical reduction (presence of Fe 2+) without changing the band gap. We demonstrate that these changes are profitable and correlated to the drastic changes of the photocatalytic activity.

Published
2015
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8. X-ray analysis of the magnetic influence of oxygen in Pt/Co/AlOx trilayers

Author

Aurelien Manchon, M. Hochstrasser, B. Dieny, G. Panaccione, Clarisse Ducruet, Stéphane Auffret, Stefania Pizzini, B. Rodmacq, Vojtech Uhlir, Jan Vogel, Lucien Lombard, 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), 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 Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratory for Solid State Physics (ETH Zurich), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Laboratory TASC (TASC), INFM-CNR, Micro et NanoMagnétisme (NEEL - MNM), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Nanostructure, oxidation, perpendicular magnetic anisotropy, Analytical chemistry, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, Oxygen, PACS: 75.70.Cn, 75.30.Gw, 79.60.Jv, 81.65.Mq, Condensed Matter::Materials Science, X-ray photoelectron spectroscopy, 0103 physical sciences, platinum, 010306 general physics, Spectroscopy, magnetic multilayers, MAGNETOCRYSTALLINE ANISOTROPY, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall], TUNNEL-JUNCTION, X-ray photoelectron spectra, Heterojunction, PERPENDICULAR ANISOTROPY, aluminium compounds, 021001 nanoscience & nanotechnology, ORBITAL-MOMENT, cobalt, Magnetic anisotropy, chemistry, AU MULTILAYERS, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Platinum, Cobalt
Abstract

International audience; X-ray spectroscopy measurements have been performed on a series of Pt/Co/AlOx trilayers to investigate the role of Co oxidation in the perpendicular magnetic anisotropy at the Co/AlOx interface. It is observed that varying the degree of oxidation modifies the magnetic properties of the Co layer, inducing a magnetic anisotropy crossover from in plane to out of plane. The microscopic structural properties are analyzed via x-ray photoelectron spectroscopy measurements. It is shown that increasing the oxidation time enhances the amount of interfacial oxide, which may be at the origin of perpendicular magnetic anisotropy.

Published
2008
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9. Structural, magnetic and spectroscopic study of a diluted magnetic oxide: Co doped CeO2−δ

Author

A. J. A. de Oliveira, Boris Vodungbo, Dominique Demaille, J. Varalda, Y. Zheng, Massimiliano Marangolo, Franck Vidal, Francesco Maccherozzi, Victor H. Etgens, G. Panaccione, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Departamento de Fisica, Universidade Federal de Sao Carlos, TASC - Laboratory TASC, INFM-CNR, and Universidade Federal de São Carlos [São Carlos] (UFSCar)

Subjects
Materials science, Condensed matter physics, Doping, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Pulsed laser deposition, Magnetization, Magnetic anisotropy, Condensed Matter::Materials Science, Ferromagnetism, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], General Materials Science, Condensed Matter::Strongly Correlated Electrons, Thin film, 010306 general physics, 0210 nano-technology, Saturation (magnetic), Superparamagnetism
Abstract

International audience; A structural, spectroscopic and magnetic study of Co doped CeO2−δ diluted magnetic oxide (DMO) thin films grown by pulsed laser deposition is presented. No secondary phase or metallic clusters could be detected. The samples are ferromagnetic at room temperature and epitaxial films display a large magnetic anisotropy with an out-of-plane easy axis. The evolution of the magnetization with temperature did not reveal any superparamagnetic signal related to nanosized clusters, reinforcing the conclusion that the ferromagnetism is intrinsic in this system. The magnetization at saturation has the same magnitude (~1.4–1.5 μB/Co) in epilayers and textured films and shows no clear dependence on the structural quality, contrary to other DMOs. It is also shown that ferromagnetism is not restricted to a particular region of the films, such as the interface. The ferromagnetic signal depends sensitively on the oxygen pressure during growth and post-growth annealing. The valence of Ce and Co was deduced from x-ray spectroscopies, revealing a predominant Co2+ state. The origin of ferromagnetism in Co doped CeO2−δ is discussed in connection with possible charge-compensating defects and existing models describing indirect exchange in DMOs.

Published
2008
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10. X-Ray Analysis of Oxygen-induced Perpendicular Magnetic Anisotropy in Pt/Co/AlOx trilayer

Author

Aurélien Manchon, Stefania Pizzini, Jan Vogel, Vojtech Uhlir, Lucien Lombard, Clarisse Ducruet, Stéphane Auffret, Bernard Rodmacq, Bernard Dieny, Michael Hochstrasser, Giancarlo Panaccione, 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), Micro et NanoMagnétisme (NEEL - MNM), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Institute of Physical Engineering, Brno University of Technology [Brno] (BUT), Laboratory for Solid State Physics, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Laboratory TASC, INFM-CNR, Micro et NanoMagnétisme (MNM), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)

Subjects
Condensed Matter - Materials Science, 75.47.-m,75.70.Cn,72.25.Ba,73.20.-r,73.40.Rw, Condensed Matter - Mesoscale and Nanoscale Physics, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, X-ray photoelectron spectroscopy (XPS), Condensed Matter::Materials Science, X-ray magnetic Circular Dichroism (XMCD), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), X-ray Absorption spectroscopy (XAS), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Perpendicular Magnetic Anisotropy, Magnetic Tunnel Junctions, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall]
Abstract

International audience; X-ray spectroscopy measurements have been performed on a series of Pt/Co/AlOx trilayers to investigate the role of Co oxidation in the perpendicular magnetic anisotropy of the Co/AlOx interface. It is observed that high temperature annealing modifies the magnetic properties of the Co layer, inducing an enhancement of the perpendicular magnetic anisotropy. The microscopic structural properties are analyzed via X-ray Absorption Spectroscopy, X-ray Magnetic Circular Dichroism and X-ray Photoelectron Spectroscopy measurements. It is shown that annealing enhances the amount of interfacial oxide, which may be at the origin of a strong perpendicular magnetic anisotropy.

Published
2007
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11. Analysis of anisotropy crossover due to oxygen in Pt/Co/MOx trilayer

Author

Aurélien Manchon, Clarisse Ducruet, Lucien Lombard, Stéphane Auffret, Bernard Rodmacq, Bernard Dieny, Stefania Pizzini, Jan Vogel, Vojtech Uhlir, Michael Hochstrasser, Giancarlo Panaccione, 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), Consortium de Recherches pour l'Emergence des Technologies Avancées (CRETA), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Micro et NanoMagnétisme (NEEL - MNM), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Laboratory for Solid State Physics, Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Laboratory TASC, INFM-CNR, Micro et NanoMagnétisme (MNM), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)

Subjects
Condensed Matter - Materials Science, X-ray photoelectron spectroscopy, Magnetic tunnel junctions, Condensed Matter::Materials Science, 75.47.-m,75.70.Cn,72.25.Ba,73.20.-r,73.40.Rw, Condensed Matter - Mesoscale and Nanoscale Physics, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], X-ray absorption spectroscopy, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Perpendicular magnetic anisotropy, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall]
Abstract

International audience; Extraordinary Hall effect and X-ray spectroscopy measurements have been performed on a series of Pt/Co/MOx trilayers (M=Al, Mg, Ta...) in order to investigate the role of oxidation in the onset of perpendicular magnetic anisotropy at the Co/MOx interface. It is observed that varying the oxidation time modifies the magnetic properties of the Co layer, inducing a magnetic anisotropy crossover from in-plane to out-of-plane. We focused on the influence of plasma oxidation on Pt/Co/AlOx perpendicular magnetic anisotropy. The interfacial electronic structure is analyzed via X-ray photoelectron spectroscopy measurements. It is shown that the maximum of out-of-plane magnetic anisotropy corresponds to the appearance of a significant density of Co-O bondings at the Co/AlOx interface.

Published
2007
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12. Photoelectron spectroscopy study of Pb/Ag(111) in the submonolayer range

Author

G. Le Lay, Guy Tréglia, G. Panaccione, J. Dalmas, Hamid Oughaddou, Jean Bernardini, Bernard Aufray, Christophe Girardeaux, Jun Fujii, ISMO, Institut des Sciences Moléculaires d'Orsay (ISMO), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU), Laboratoire matériaux et microélectronique de Provence (L2MP), Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), TASC national laboratory, Trieste, Laboratory TASC (TASC), INFM-CNR, Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Low-energy electron diffraction, Chemistry, Alloy, Analytical chemistry, Synchrotron radiation, 02 engineering and technology, Surfaces and Interfaces, engineering.material, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Spectral line, Surfaces, Coatings and Films, Overlayer, Crystallography, Vacuum deposition, X-ray photoelectron spectroscopy, 0103 physical sciences, Monolayer, Materials Chemistry, engineering, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 010306 general physics, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS
Abstract

The vacuum deposition of Pb onto Ag(1 1 1) gives rise to two different surface structures depending on coverage and deposition temperature. At room temperature (RT), low energy electron diffraction (LEED) reveals a sharp ( 3 × 3 ) R 30 ° reconstruction completed at 1/3 Pb monolayer (ML). Beyond, a close-packed Pb(1 1 1) incommensurate overlayer develops. At low temperature (LT, ∼100 K) the incommensurate structure is directly observed whatever the coverage, corresponding to the growth of close-packed two-dimensional Pb(1 1 1) islands. Synchrotron radiation Pb 5d core-level spectra clearly demonstrate that in each surface structure all Pb atoms have essentially a unique, but different, environment. This reflects the surface alloy formation between the two immiscible metals in the ( 3 × 3 ) R 30 ° reconstruction and a clear signature of the de-alloying process at RT beyond 1/3 ML coverage.

Published
2006
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13. Orbital Mapping of Semiconducting Perylenes on Cu(111).

Author

Di Santo G, Miletić T, Schwendt M, Zhou Y, Kariuki BM, Harris KDM, Floreano L, Goldoni A, Puschnig P, Petaccia L, and Bonifazi D

Abstract

Semiconducting O-doped polycyclic aromatic hydrocarbons constitute a class of molecules whose optoelectronic properties can be tailored by acting on the π-extension of the carbon-based frameworks and on the oxygen linkages. Although much is known about their photophysical and electrochemical properties in solution, their self-assembly interfacial behavior on solid substrates has remained unexplored so far. In this paper, we have focused our attention on the on-surface self-assembly of O-doped bi-perylene derivatives. Their ability to assemble in ordered networks on Cu(111) single-crystalline surfaces allowed a combination of structural, morphological, and spectroscopic studies. In particular, the exploitation of the orbital mapping methodology based on angle-resolved photoemission spectroscopy, with the support of scanning tunneling microscopy and low-energy electron diffraction, allowed the identification of both the electronic structure of the adsorbates and their geometric arrangement. Our multi-technique experimental investigation includes the structure determination from powder X-ray diffraction data for a specific compound and demonstrates that the electronic structure of such large molecular self-assembled networks can be studied using the reconstruction methods of molecular orbitals from photoemission data even in the presence of segregated chiral domains., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Published
2021
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