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1. Superstructures, Commensurations, and Rotation of Single-Layer TaS 2 on Au(111) Induced by Cs Intercalation/Deintercalation

Author

Xiaorong Weng, Philippe David, Valérie Guisset, Lucio Martinelli, Olivier Geaymond, Johann Coraux, Gilles Renaud, Nanostructures et Rayons X (NRX), Modélisation et Exploration des Matériaux (MEM), 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)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)

Subjects
[PHYS]Physics [physics], General Engineering, General Physics and Astronomy, General Materials Science
Abstract

International audience

Published
2023
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2. Decoupling Molybdenum Disulfide from Its Substrate by Cesium Intercalation

Author

Simone Lisi, Marco Bianchi, Olivier Geaymond, Valérie Guisset, Johann Coraux, Estelle Mazaleyrat, Ana Cristina Gómez Herrero, Van-Dung Nguyen, Gilles Renaud, Claude Chapelier, Roberto Sant, Matthieu Jamet, Philip Hofmann, Laurence Magaud, Philippe David, Yannick J. Dappe, Alain Marty, Systèmes hybrides de basse dimensionnalité (HYBRID), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), 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), CRG et Grands Instruments (CRG), Epitaxie et couches minces (EpiCM), SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Laboratoire de Transport Electronique Quantique et Supraconductivité (LaTEQS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Groupe Modélisation et Théorie (GMT), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-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)-Centre National de la Recherche Scientifique (CNRS), Interdisciplinary Nanoscience Center (iNANO), Aarhus University [Aarhus], Nanostructures et Rayonnement Synchrotron (NRS ), Modélisation et Exploration des Matériaux (MEM), Systèmes hybrides de basse dimensionnalité (NEEL - HYBRID), CRG & Grands instruments (NEEL - CRG), Epitaxie et couches minces (NEEL- EpiCM), 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), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Materials science, Intercalation (chemistry), Surface X-ray Diffraction, chemistry.chemical_element, FOS: Physical sciences, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, chemistry.chemical_compound, Molybdenum Disulfide, Transition metal, Intercalation, Lamellar structure, Physical and Theoretical Chemistry, Molybdenum disulfide, Condensed Matter - Materials Science, Substrate (chemistry), Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Crystallography, General Energy, chemistry, Scanning Tunneling Microscopy, Caesium, Density functional theory, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Decoupling (electronics)
Abstract

Intercalation of alkali atoms within the lamellar transition metal dichalcogenides is a possible route toward a new generation of batteries. It is also a way to induce structural phase transitions authorizing the realization of optical and electrical switches in this class of materials. The process of intercalation has been mostly studied in three-dimensional dichalcogenide films. Here, we address the case of a single-layer of molybdenum disulfide (MoS$_2$), deposited on a gold substrate, and intercalated with cesium (Cs) in ultra-clean conditions (ultrahigh vacuum). We show that intercalation decouples MoS$_2$ from its substrate. We reveal electron transfer from Cs to MoS$_2$, relative changes in the energy of the valence band maxima, and electronic disorder induced by structural disorder in the intercalated Cs layer. Besides, we find an abnormal lattice expansion of MoS$_2$, which we relate to immediate vicinity of Cs. Intercalation is thermally activated, and so is the reverse process of de-intercalation. Our work opens the route to a microscopic understanding of a process of relevance in several possible future technologies, and shows a way to manipulate the properties of two-dimensional dichalcogenides by "under-cover" functionalization., Comment: 6 figures

Published
2020
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3. In Situ X-ray Diffraction Study of GaN Nucleation on Transferred Graphene

Author

Patrick Le Fèvre, Tao Zhou, Jean-Christophe Harmand, Ludovic Largeau, Noelle Gogneau, Frank Glas, Ali Madouri, Olivier Geaymond, Maria Tchernycheva, Laurent Travers, Martina Morassi, Antonella Cavanna, Camille Barbier, and Gilles Renaud

Subjects
In situ, Diffraction, Materials science, 010405 organic chemistry, business.industry, Graphene, Nanowire, Nucleation, General Chemistry, Substrate (electronics), 010402 general chemistry, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, law.invention, law, X-ray crystallography, Optoelectronics, General Materials Science, Crystallite, business
Abstract

We investigate by in situ X-ray diffraction the early stage of GaN nanowire growth on a single layer of polycrystalline graphene transferred onto a Si(100)/SiO2 carrier substrate. The experiment wa...

Published
2020
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4. A high-pressure high-temperature setup for in situ Raman spectroscopy of supercritical fluids

Author

Olivier Geaymond, Roger Argoud, Denis Testemale, Jean-Louis Hazemann, Marion Louvel, Eric Lahera, William Del Net, Amélie Bordage, Jean Dubessy, Cécile Da Silva-Cadoux, MRS - Matériaux, Rayonnements, Structure, Institut Néel (NEEL), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), CRG - CRG et Grands Instruments, GeoRessources, Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Matériaux, Rayonnements, Structure (MRS), 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), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), and CRG et Grands Instruments (CRG)

Subjects
In situ, Analytical chemistry, 02 engineering and technology, 01 natural sciences, Autoclave, law.invention, symbols.namesake, law, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, 0103 physical sciences, Materials Chemistry, H2O, Physical and Theoretical Chemistry, Absorption (electromagnetic radiation), In situ HP/HT experiments, Spectroscopy, ComputingMilieux_MISCELLANEOUS, Supercritical fluids, 010304 chemical physics, Chemistry, Scattering, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Laser, Atomic and Molecular Physics, and Optics, Supercritical fluid, Electronic, Optical and Magnetic Materials, Raman spectroscopy, symbols, CO2, 0210 nano-technology, Raman scattering
Abstract

A high-pressure/high-temperature cell dedicated to Raman spectroscopy is presented. The P and T ranges are optimized for the study of supercritical fluids (T ≤ 975 K, P ≤ 200 MPa); the P and T parameters are controlled independently. The autoclave was adapted from a previous cell (designed for X-ray absorption and scattering spectroscopies) to answer the specific requirement of Raman spectroscopy. Original high pressure windows and sample cell have been developed to ensure both pressure resistance and transparency for the optical laser and Raman scattering beams. An optical integration of the autoclave in the Raman spectrometer setup was designed to perform in situ Raman experiments on fluids. The spectroscopic measurements can be combined with visual observation, which is particularly useful for the study of multi-phasic systems. As examples of the efficiency of the set-up and its scientific opportunities, we present Raman measurements on water, carbon dioxide and mixed H2O–CO2 system obtained from ambient to supercritical conditions.

Published
2015
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5. X-ray absorption spectroscopy studies of ionic association in aqueous solutions of zinc bromide from normal to critical conditions

Author

D. Raoux, Y. Calzavara, V. Simonet, Olivier Geaymond, J. L. Hazemann, and Roger Argoud

Subjects
X-ray absorption spectroscopy, Aqueous solution, Absorption edge, Extended X-ray absorption fine structure, Absorption spectroscopy, Chemistry, Analytical chemistry, General Physics and Astronomy, Physical and Theoretical Chemistry, Absorption (chemistry), Supercritical fluid, XANES
Abstract

Ion-pairing and dehydration phenomena occurring in ZnBr2 aqueous solutions from normal to critical T, P conditions were investigated by x-ray absorption spectroscopy. The respective influences of temperature, pressure, and concentration were studied. The evolution of the density of solute ions, probed by the height of the absorption edge, allowed us to get information on phase diagrams and salt precipitation. The average structural evolution deduced from extended x-ray absorption fine structure was related to the formation of complexes identified from x-ray absorption near edge structure analysis. Consequently, in noncritical conditions, an increase of temperature or concentration produces dehydration and ion-pairing, while a rise of pressure destroys the ion-pairs. In contrast, concentration and pressure have weaker effects on the local order in high P, T conditions. Moreover, ion pairing formation is found not to be specifically enhanced when the fluid is close to supercritical conditions as it also occ...

Published
2002
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6. Structure of aqueous ZnBr2 solution probed by x-ray absorption spectroscopy in normal and hydrothermal conditions

Author

Y. Calzavara, D. Raoux, Olivier Geaymond, V. Simonet, J. L. Hazemann, and Roger Argoud

Subjects
X-ray absorption spectroscopy, Crystallography, Aqueous solution, Absorption spectroscopy, Extended X-ray absorption fine structure, Octahedron, Chemistry, General Physics and Astronomy, Physical and Theoretical Chemistry, Absorption (chemistry), Hydrothermal circulation, X-ray absorption fine structure
Abstract

Local-order evolution around ions in aqueous solutions has been investigated between normal and hydrothermal conditions. The behavior of cations and anions in aqueous ZnBr2 solution were studied by performing x-ray absorption spectroscopy experiments at both Br and Zn edges. Extended x-ray absorption fine structure analyses are made on account of anharmonic treatment and multiple scattering contributions involving H atoms at the Br edge. The extended x-ray absorption fine structure results are coupled to x-ray absorption near-edge structure simulations in order to identify the complexes formed under normal and hydrothermal conditions. It appears that both Zn and Br ions are largely hydrated under normal conditions and that Zn–Br pairs are formed in hydrothermal conditions. This is related to an octahedral-to-tetrahedral evolution of the Zn local environment, the majority of Zn atoms being surrounded by water octahedra in normal conditions and by distorted tetrahedra involving Br and O atoms in hydrotherma...

Published
2002
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7. Laue microdiffraction at the ESRF

Author

Olivier Sicardy, M. Olivier Geaymond, Odile Robach, Michel Bornert, Olivier Castelnau, J. Petit, M. Olivier Ulrich, François Rieutord, X. Biquard, Jean Sébastien Micha, Sophie Berveiller, Julie Villanova, Christoph Kirchlechner, European Synchrotron Radiation Facility (ESRF), Nanostructures et Rayonnement Synchrotron (NRS ), Modélisation et Exploration des Matériaux (MEM), 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 [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Montanuniversität Leoben (MUL), University of Leoben (MU), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Synthèse, Structure et Propriétés de Matériaux Fonctionnels (STEP), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), CRG et Grands Instruments (CRG), 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), Laboratoire Procédés et Ingénierie en Mécanique et Matériaux (PIMM), Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), Laboratoire Navier (navier umr 8205), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Energétique Mécanique Electromagnétisme (LEME), Université Paris Nanterre (UPN), Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Arts et Métiers Sciences et Technologies, Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Centre Science des Matériaux et des Structures (SMS-ENSMSE), École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Département Microstructures et Propriétés Mécaniques (MPM-ENSMSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-SMS, Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Gesellschaft, Laboratoire de mécanique des solides (LMS), École polytechnique (X)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Centre Hospitalier Universitaire de Dijon - Hôpital François Mitterrand (CHU Dijon), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), ARC-Nucleart CEA Grenoble (NUCLEART), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de L'Energie Solaire (INES), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), CRG & Grands instruments (NEEL - CRG), Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), and HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)

Subjects
010302 applied physics, Diffraction, Materials science, Synchrotron radiation, business.industry, Orientation (computer vision), Resolution (electron density), 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Displacement (vector), diffraction contrast, Reciprocal lattice, [SPI]Engineering Sciences [physics], Optics, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Dislocation, 0210 nano-technology, business, Focus (optics), ComputingMilieux_MISCELLANEOUS
Abstract

International audience; This book highlights emerging diffraction studies of strain and dislocation gradients with mesoscale resolution, which is currently a focus of research at laboratories around the world. While ensemble-average diffraction techniques are mature, grain and subgrain level measurements needed to understand real materials are just emerging. In order to understand the diffraction signature of different defects, it is necessary to understand the distortions created by the defects and the corresponding changes in the reciprocal space of the non-ideal crystals. Starting with a review of defect classifications based on their displacement fields, this book then provides connections between different dislocation arrangements, including geometrically necessary and statistically stored dislocations, and other common defects and the corresponding changes in the reciprocal space and diffraction patterns. Subsequent chapters provide an overview of microdiffraction techniques developed during the last decade to extract information about strain and dislocation gradients. X-ray microdiffraction is a particularly exciting application compared with alternative probes of local crystalline structure, orientation and defect density, because it is inherently non-destructive and penetrating.

Published
2014
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8. Local deformations and incommensurability of high quality epitaxial graphene on a weakly interacting transition metal

Author

Olivier Geaymond, Nils Blanc, Johann Coraux, Alpha T. N'Diaye, Chi Vo-Van, Gilles Renaud, Institut Nanosciences et Cryogénie (INAC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Systèmes hybrides de basse dimensionnalité (NEEL - HYBRID), 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), Micro et NanoMagnétisme (NEEL - MNM), University of Cologne, CRG & Grands instruments (NEEL - CRG), Systèmes hybrides de basse dimensionnalité (HYBRID), 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), Micro et NanoMagnétisme (MNM), and CRG et Grands Instruments (CRG)

Subjects
Diffraction, Condensed Matter - Materials Science, Materials science, Condensed matter physics, Graphene, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, chemistry.chemical_element, Substrate (electronics), Condensed Matter Physics, 01 natural sciences, Thermal expansion, 010305 fluids & plasmas, Electronic, Optical and Magnetic Materials, law.invention, Lattice constant, Transition metal, chemistry, law, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Iridium, Scanning tunneling microscope, 010306 general physics
Abstract

We investigate the fine structure of graphene on iridium, which is a model for graphene weakly interacting with a transition-metal substrate. Even the highest-quality epitaxial graphene displays tiny imperfections, i.e., small biaxial strains of $\ensuremath{\sim}$0.3$%$, rotations of $\ensuremath{\sim}$0.5${}^{\ensuremath{\circ}}$, and shears over distances of $\ensuremath{\sim}$100 nm, and is found incommensurate, as revealed by x-ray diffraction and scanning tunneling microscopy. These structural variations are mostly induced by the increase of the lattice parameter mismatch when cooling the sample from the graphene preparation temperature to the measurement temperature. Although graphene weakly interacts with iridium, its thermal expansion is found to be positive, contrary to free-standing graphene. The structure of graphene and its variations is very sensitive to the preparation conditions. All these effects are consistent with initial growth and subsequent pinning of graphene at steps.

Published
2012
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9. High pressure/high temperature cell for x-ray absorption and scattering techniques

Author

Olivier Geaymond, Denis Testemale, Roger Argoud, Jean-Louis Hazemann, Laboratoire de Cristallographie, and Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Absorption spectroscopy, Extended X-ray absorption fine structure, business.industry, Scattering, [SDE.MCG]Environmental Sciences/Global Changes, Analytical chemistry, 02 engineering and technology, 010502 geochemistry & geophysics, 021001 nanoscience & nanotechnology, 01 natural sciences, Supercritical fluid, Absorbance, Optics, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Small-angle scattering, 0210 nano-technology, Absorption (electromagnetic radiation), business, Instrumentation, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Bar (unit)
Abstract

A high pressure/high temperature cell dedicated to x-ray absorption spectroscopy, small angle x-ray scattering, and inelastic x-ray scattering techniques is presented. The P and T parameters are controlled independently and their range allow the study of aqueous solutions (T⩽500°C and P⩽2000bar) and liquid metals and glasses (T⩽1700°C and P⩽2000bar). The autoclave technology is inspired from previous high pressure/high temperature equipments but great improvements are achieved. Original high pressure windows have been developed to ensure both pressure resistance and low absorbance combined with large angular aperture. Different configurations are available for the internal cell that contains the sample whether it is aqueous or not. As an example of the efficiency of the set-up, we present preliminary x-ray absorption results on 0.01 m FeCl3 aqueous solutions from ambient to supercritical conditions (375 °C and 300 bar). These low concentrations samples and low energy spectra (Fe K-edge is at 7112 eV) repr...

Published
2005
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10. Structural and electronic evolution of the As(OH)3 molecule in high temperature aqueous solutions: an x-ray absorption investigation

Author

Jean-Louis Hazemann, Olivier Geaymond, Gleb S. Pokrovski, Denis Testemale, Jacques Roux, Roger Argoud, and Yves Joly

Subjects
X-ray absorption spectroscopy, Crystallography, Molecular geometry, Absorption spectroscopy, Extended X-ray absorption fine structure, Chemistry, General Physics and Astronomy, Physical chemistry, Molecule, Electronic structure, Physical and Theoretical Chemistry, Absorption (chemistry), XANES
Abstract

The geometrical and electronic structure of the arsenious acid molecule As(OH)(3) in aqueous solutions has been investigated by x-ray absorption spectroscopy (XAS) within extended x-ray absorption spectroscopy (EXAFS) and x-ray absorption near edge structure (XANES), using realistic first-principle calculations in the latter case. This investigation was performed on aqueous solutions of arsenious acid from ambient to supercritical conditions (P = 250 and 600 bars, Tor= 500 degrees C) using a new optical cell. The analysis of the XAS spectra is consistent with (1) a constant As-O distance, (2) an opening of the O-As-O angles within the C(3V) pyramidal structure in the range 30-200 degrees C. This structural evolution comes along with a small decrease of the partial charges of the atoms in the As(OH)(3) molecule. The explanation invoked for both structural and electronic modifications observed is the weakening of the interactions, through hydrogen bonds, between the As(OH)(3) complex and water molecules. This is a fingerprint of the similar weakening of hydrogen bonding interactions in the solvent itself.

Published
2004

11. Small angle x-ray scattering of a supercritical electrolyte solution: The effect of density fluctuations on the hydration of ions

Author

Marie-Vanessa Coulet, Roger Argoud, Jean Paul Simon, Françoise Bley, Jean Louis Hazemann, Olivier Geaymond, and Denis Testemale

Subjects
Aqueous solution, 010304 chemical physics, Small-angle X-ray scattering, Scattering, Chemistry, General Physics and Astronomy, Thermodynamics, 02 engineering and technology, Electrolyte, 021001 nanoscience & nanotechnology, 01 natural sciences, Critical point (mathematics), Supercritical fluid, Crystallography, 0103 physical sciences, Isobar, Physical and Theoretical Chemistry, 0210 nano-technology, Structure factor
Abstract

Synchrotron small angle x-ray scattering measurements on water and zinc bromide ZnBr2 aqueous solutions were carried out from ambient to supercritical conditions. For both systems several isobars (between 285 and 600 bars) were followed beyond the critical isochore. The data were analyzed through an Ornstein-Zernike formalism in terms of correlation length and null angle structure factor. The results for pure water are in agreement with previously published values. Solutions of different electrolyte concentrations were studied. In each case, the values of the correlation length and null angle structure factor are larger than those of pure water. This effect is more pronounced for higher concentrations and/or for pressure closer to the critical point of pure water. This is in agreement with the shift of the critical point determined in the literature for NaCl solutions. Comparing these results to previous x-ray absorption measurements carried out on identical samples we propose the following two step sequence for ionic hydration up to supercritical conditions: (1) from ambient to about 300 degrees C, an increase of ion pairing and formation of multi-ionic complexes which can be correlated to the decrease of the dielectric constant; (2) an enhancement of the local solvation shell of ions due to the onset of the thermal density fluctuations at high temperature, leading to a screening effect between ions and inhibiting the ion pairing processes.

Published
2005
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