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2. Successive incommensurate spin orderings and excitations in multiferroic SrMnGe2O6

Author

Colin, Claire V., Ding, Lei, Ressouche, Eric, Robert, Julien, Terada, Noriki, Gay, Frederic, Lejay, Pascal, Simonet, Virginie, Darie, Céline, Bordet, Pierre, and Petit, Sylvain

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Materials Science
Abstract

Anisotropic multiferroic properties of SrMnGe2O6 pyroxene single crystals were systematically investigated by means of magnetization, heat capacity, pyroelectric current measurement and elastic and inelastic neutron scattering experiments. Single crystal neutron diffraction allows us to unambiguously reveal the presence of two incommensurate magnetic orderings: a non-polar amplitude-modulated collinear sinusoidal magnetic structure emerges at TN1=4.36(2)K followed by a polar elliptical cycloidal spin structure below TN2=4.05(2)K. Pyroelectric current measurements on single crystal confirm the appearance of a spontaneous polarization within the (ac) plane below TN2 associated with the latter magnetic symmetry through extended Dzyaloshinsky-Moriya mechanism. The magnetic phase diagram was calculated considering the three isotropic exchange couplings relevant in this system. The magnetic excitations spectra of SrMnGe2O6 measured by inelastic neutron scattering were successfully modeled using a set of exchange interactions consistent with this phase diagram.

Published
2019
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6. X-ray diffraction and heterogeneous materials: An adaptive crystallography approach

Author

Dejoie, Catherine, Autran, Pierre-Olivier, Bordet, Pierre, Fitch, Andy N, Martinetto, Pauline, Sciau, Philippe, Tamura, Nobumichi, and Wright, Jonathan

Subjects
Mathematical Sciences, Physical Sciences, Generic health relevance, Cultural heritage, Heterogeneous materials, X-ray diffraction, Crystalline phases, Amorphous phases, Synchrotron, Fluids & Plasmas, Mathematical sciences, Physical sciences
Abstract

Cultural heritage materials are often complex and heterogeneous, with a multi-scale architecture. Phases from a variety of crystalline forms co-exist in a wide grain size distribution, with each of these phases keeping in their structural arrangement a memory of the transformations that occurred to the material. Over the last two decades, X-ray diffraction has been applied successfully to the study of cultural heritage materials, with the use of synchrotron facilities offering new possibilities to describe the structural features of such complex materials. The long-range and/or short-range organization of the different crystallographic phases as well as their global position/dispersion in the material are closely related to the properties of the material (optical, mechanical…), its manufacturing process, functionality, or long-term conservation. In this paper, possible diffraction setups and data collection strategies are discussed in order to retrieve adequate data from crystalline and amorphous phases and to take into account single-crystal contributions.

Published
2018

8. Unlocking mixed oxides with unprecedented stoichiometries from heterometallic metal-organic frameworks for the catalytic hydrogenation of CO2

Author

Castells-Gil, Javier, Ould-Chikh, Samy, Ramírez, Adrian, Ahmad, Rafia, Prieto, Gonzalo, Gómez, Alberto Rodríguez, Garzón-Tovar, Luis, Telalovic, Selvedin, Liu, Lingmei, Genovese, Alessandro, Padial, Natalia M., Aguilar-Tapia, Antonio, Bordet, Pierre, Cavallo, Luigi, Martí-Gastaldo, Carlos, and Gascon, Jorge

Published
2021
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9. A new high pressure form of Ba3NiSb2O9

Author

Darie, Céline, Lepoittevin, Christophe, Klein, Holger, Kodjikian, Stéphanie, Bordet, Pierre, Colin, Claire V., Lebedev, Oleg I., Deudon, Catherine, and Payen, Christophe

Subjects
Condensed Matter - Materials Science
Abstract

The interest in finding experimental realization of Quantum Liquid Spin phases leads us to elaborate polycrystalline samples of the 6H-B phase of Ba3NiSb2O9 . This structure shows Ni triangular planes and the first magnetic characterizations confirm the absence of any magnetic order as expected for QLS. The samples were synthesized by treatment under HP-HT of the 6H-A phase of Ba3NiSb2O9. The optimized synthesis conditions were 2.5 GPa and 620{\deg}C. By combining several technics as XRD, NPD and TEM we show that even the obtained compound is in fact a new form of Ba3NiSb2O9, that corresponds to a new stacking along c. This preserves the presence of Ni planes but results in a loss of the hexagonal symmetry. The TEM is helpful to conclude to a trigonal symmetry at a scale of 10nm., Comment: 5 figures submitted to Journal of Solid State Chemistry on 9/12/2015_ revised version on 30/01/2016

Published
2016
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10. Neural networks for rapid phase quantification of cultural heritage X‐ray powder diffraction data.

Author

Poline, Victor, Purushottam Raj Purohit, Ravi Raj Purohit, Bordet, Pierre, Blanc, Nils, and Martinetto, Pauline

Subjects
X-ray powder diffraction, COMPUTED tomography, CULTURAL property, RIETVELD refinement, NONNEGATIVE matrices, MATRIX decomposition
Abstract

Recent developments in synchrotron radiation facilities have increased the amount of data generated during acquisitions considerably, requiring fast and efficient data processing techniques. Here, the application of dense neural networks (DNNs) to data treatment of X‐ray diffraction computed tomography (XRD‐CT) experiments is presented. Processing involves mapping the phases in a tomographic slice by predicting the phase fraction in each individual pixel. DNNs were trained on sets of calculated XRD patterns generated using a Python algorithm developed in‐house. An initial Rietveld refinement of the tomographic slice sum pattern provides additional information (peak widths and integrated intensities for each phase) to improve the generation of simulated patterns and make them closer to real data. A grid search was used to optimize the network architecture and demonstrated that a single fully connected dense layer was sufficient to accurately determine phase proportions. This DNN was used on the XRD‐CT acquisition of a mock‐up and a historical sample of highly heterogeneous multi‐layered decoration of a late medieval statue, called 'applied brocade'. The phase maps predicted by the DNN were in good agreement with other methods, such as non‐negative matrix factorization and serial Rietveld refinements performed with TOPAS, and outperformed them in terms of speed and efficiency. The method was evaluated by regenerating experimental patterns from predictions and using the R‐weighted profile as the agreement factor. This assessment allowed us to confirm the accuracy of the results. [ABSTRACT FROM AUTHOR]

Published
2024
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11. Jahn-Teller, polarity and insulator-to-metal transition in BiMnO3 at high pressure

Author

Guennou, Mael, Bouvier, Pierre, Toulemonde, Pierre, Darie, Céline, Goujon, Céline, Bordet, Pierre, Hanfland, Michael, and Kreisel, Jens

Subjects
Condensed Matter - Materials Science
Abstract

The interaction of coexisting structural instabilities in multiferroic materials gives rise to intriguing coupling phenomena and extraordinarily rich phase diagrams, both in bulk materials and strained thin films. Here we investigate the multiferroic BiMnO3 with its peculiar 6s2 electrons and four interacting mechanisms: electric polarity, octahedra tilts, magnetism, and cooperative Jahn-Teller distortion. We have probed structural transitions under high pressure by synchrotron x-ray diffraction and Raman spectroscopy up to 60 GPa. We show that BiMnO3 displays under pressure a rich sequence of five phases with a great variety of structures and properties, including a metallic phase above 53 GPa and, between 37 and 53 GPa, a strongly elongated monoclinic phase that allows ferroelectricity, which contradicts the traditional expectation that ferroelectricity vanishes under pressure. Between 7 and 37 GPa, the Pnma structure remains remarkably stable but shows a reduction of the Jahn-Teller distortion in a way that differs from the behavior observed in the archetypal orthorhombic Jahn-Teller distorted perovskite LaMnO3., Comment: 5 pages, 3 figures + supplemental material included (3 pages, 1 figure, 3 tables)

Published
2013
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12. Parity Broken Chiral Spin Dynamics in Ba$_3$NbFe$_3$Si$_2$O$_{14}$

Author

Loire, Mickael, Simonet, Virginie, Petit, Sylvain, Marty, Karol, Bordet, Pierre, Lejay, Pascal, Ollivier, Jacques, Enderle, Mechthild, Steffens, Paul, Ressouche, Eric, Zorko, Andrej, and Ballou, Rafik

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The spin wave excitations emerging from the chiral helically modulated 120$^{\circ}$ magnetic order in a langasite Ba$_3$NbFe$_3$Si$_2$O$_{14}$ enantiopure crystal were investigated by unpolarized and polarized inelastic neutron scattering. A dynamical fingerprint of the chiral ground state is obtained, singularized by (i) spectral weight asymmetries answerable to the structural chirality and (ii) a full chirality of the spin correlations observed over the whole energy spectrum. The intrinsic chiral nature of the spin waves elementary excitations is shown in absence of macroscopic time reversal symmetry breaking.

Published
2010
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13. Magnetic phase diagram of the S=1/2 triangular layered compound NaNiO2: a single crystal study

Author

De Brion, Sophie, Bonda, Markus, Darie, Céline, Bordet, Pierre, and Sheikin, Ilya

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

Using magnetic torque measurement on a NaNiO2 single crystal, we have established the magnetic phase diagram of this triangular compound. It presents 5 different phases depending on the temperature (4 K - 300 K) and magnetic field (0 - 22 T) revealing several spin reorientations coupled to different magnetic anisotropies.

Published
2010
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14. Magnetic structure and charge ordering in Fe3BO5 ludwigite

Author

Bordet, Pierre and Suard, Emmanuelle

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The crystal and magnetic structures of the three-leg ladder compound Fe3BO5 have been investigated by single crystal x-ray diffraction and neutron powder diffraction. Fe3BO5 contains two types of three-leg spin ladders. It shows a charge ordering transition at 283 K, an antiferromagnetic transition at 112 K, ferromagnetism below 70 K and a weak ferromagnetic behavior below 40K. The x-ray data reveal a smooth charge ordering and an incomplete charge localization down to 110K. Below the first magnetic transition, the first type of ladders orders as ferromagnetically coupled antiferromagnetic chains, while below 70K the second type of ladders orders as antiferromagnetically coupled ferromagnetic chains.

Published
2009
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15. Magnetic and dielectric properties in the langasite-type compounds : A3BFe3D2O14 with A=Ba, Sr, Ca, B=Ta, Nb, Sb and D=Ge, Si

Author

Marty, Karol, Bordet, Pierre, Simonet, Virginie, Loire, Mickael, Ballou, Rafik, Darie, Céline, Kljun, Jakob, Bonville, Pierre, Isnard, Olivier, Lejay, Pascal, Zawilski, Bartosz, and Simon, Charles

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The Fe-based langasites are the first reported compounds presenting a magnetic ordering in this rich family, besides being well known for piezo-electric properties and optical activity. The structural, magnetic and dielectric properties of the Fe langasite compounds, with various substitution of non-magnetic cations, have been studied with x-ray and neutron diffraction, magnetostatic measurements, M\"ossbauer spectroscopy, and dielectric measurements. The title compounds (trigonal, space group P321) display a helical magnetic order with signatures of frustration below TN ~24- 35 K where an anomaly of the dielectric permittivity is observed. The influence of the cationic substitutions and the nature of the magnetoelectric coupling is hereafter addressed.

Published
2009
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17. Single domain magnetic helicity and triangular chirality in structurally enantiopure Ba3NbFe3Si2O14

Author

Marty, Karol, Simonet, Virginie, Ressouche, Eric, Ballou, Rafik, Lejay, Pascal, and Bordet, Pierre

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

A novel doubly chiral magnetic order is found out in the structurally chiral langasite compound Ba$_3$NbFe$_3$Si$_2$O$_{14}$. The magnetic moments are distributed over planar frustrated triangular lattices of triangle units. On each of these they form the same triangular configuration. This ferro-chiral arrangement is helically modulated from plane to plane. Unpolarized neutron scattering on a single crystal associated with spherical neutron polarimetry proved that a single triangular chirality together with a single helicity is stabilized in an enantiopure crystal. A mean field analysis allows discerning the relevance on this selection of a twist in the plane to plane supersuperexchange paths.

Published
2008
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18. Hidden magnetic frustration by quantum relaxation in anisotropic Nd-langasite

Author

Simonet, Virginie, Ballou, Rafik, Robert, Julien, Canals, Benjamin, Hippert, Françoise, Bordet, Pierre, Lejay, Pascal, Fouquet, Peter, Ollivier, Jacques, and Braithwaite, Daniel

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The static and dynamic magnetic properties of the Nd$_3$Ga$_5$SiO$_{14}$ compound, which appears as the first materialization of a rare-earth kagome-type lattice, were re-examined, owing to contradictory results in the previous studies. Neutron scattering, magnetization and specific heat measurements were performed and analyzed, in particular by fully taking account of the crystal electric field effects on the Nd$^{3+}$ ions. One of the novel findings is that the peculiar temperature independent spin dynamics observed below 10 K expresses single-ion quantum processes. This would short-circuit the frustration induced cooperative dynamics, which would emerge only at very low temperature.

Published
2008
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19. Formation of collective spins in frustrated clusters

Author

Robert, Julien, Simonet, Virginie, Canals, Benjamin, Ballou, Rafik, Lhotel, Elsa, Darie, Céline, Bordet, Pierre, Ouladdiaf, Bachir, Johnson, Marc, Ollivier, Jacques, Braithwaite, Daniel, Rakoto, Harison, and De Brion, Sophie

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

Using magnetization, specific heat and neutron scattering measurements, as well as exact calculations on realistic models, the magnetic properties of the \lacuvo compound are characterized on a wide temperature range. At high temperature, this oxide is well described by strongly correlated atomic $S$=1/2 spins while decreasing the temperature it switches to a set of weakly interacting and randomly distributed entangled pseudo spins $\tilde S=1/2$ and $\tilde S=0$. These pseudo-spins are built over frustrated clusters, similar to the kagom\'e building block, at the vertices of a triangular superlattice, the geometrical frustration intervening then at different scales., Comment: 10 pages

Published
2007
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20. Magnetic excitations in a new anisotropic Kagom\'{e} antiferromagnet

Author

Robert, Julien, Simonet, Virginie, Canals, Benjamin, Ballou, Rafik, Bordet, Pierre, Gelard, Isabelle, Ibanez, Alain, Lejay, Pascal, Ollivier, Jacques, and Stunault, Anne

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

The Nd-langasite compound contains planes of magnetic Nd3+ ions on a lattice topologically equivalent to a kagom\'{e} net. The magnetic susceptibility does not reveal any signature of long-range ordering down to 2 K but rather a correlated paramagnetism with significant antiferromagnetic interactions between the Nd and a single-ion anisotropy due to crystal field effect. Inelastic neutron scattering on Nd-langasite powder and single-crystal allowed to probe its very peculiar low temperature dynamical magnetic correlations. They present unusual dispersive features and are broadly localized in wave-vector Q revealing a structure factor associated to characteristics short range-correlations between the magnetic atoms. From comparison with theoretical calculations, these results are interpreted as a possible experimental observation of a spin liquid state in an anisotropic kagom\'{e} antiferromagnet., Comment: to appear in Physica B

Published
2006
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21. Spin liquid correlations in Nd-langasite anisotropic Kagom\'e antiferromagnet

Author

Robert, Julien, Simonet, Virginie, Canals, Benjamin, Ballou, Rafik, Bordet, Pierre, Lejay, Pascal, and Stunault, Anne

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

Dynamical magnetic correlations in the geometrically frustrated Nd$\_3$Ga$\_5$SiO$\_{14}$ compound were probed by inelastic neutron scattering on a single crystal. A scattering signal with a ring shape distribution in reciprocal space and unprecedented dispersive features was discovered. Comparison with calculated static magnetic scattering from models of correlated spins suggests that the observed phase is a spin liquid inherent to an antiferromagnetic kagom\'e-like lattice of anisotropic Nd moments., Comment: 4 pages

Published
2006
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23. Structural disorder in ORR electrocatalysis: operation mode, practical descriptors to quantify and foreseen challenges

Author

Chattot, Raphaël, Atlan, Clément, Viola, Arnaud, Chatelier, Corentin, Martens, Isaac, Roiron, Camille, Drnec, Jakub, Bordet, Pierre, Richard, Marie‐ingrid, Dubau, Laetitia, Maillard, Frédéric, Electrochimie Interfaciale et Procédés (EIP), Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces (LEPMI), Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-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)-Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-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), 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), European Synchroton Radiation Facility [Grenoble] (ESRF), Matériaux, Rayonnements, Structure (NEEL - MRS), 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 ), ANR-19-ENER-0008,BRIDGE,Vers l'intégration de catalyseurs performants dans des électrodes de pile à combustible efficaces(2019), ANR-14-CE05-0003,HOLLOW,Au-delà des électrocatalyseurs traditionnels : des nanoparticules creuses de métal noble pour applications PEMFC(2014), European Project: 818823,CARINE, Maillard, Frédéric, Vers l'intégration de catalyseurs performants dans des électrodes de pile à combustible efficaces - - BRIDGE2019 - ANR-19-ENER-0008 - ANR-BMBF - VALID, Appel à projets générique - Au-delà des électrocatalyseurs traditionnels : des nanoparticules creuses de métal noble pour applications PEMFC - - HOLLOW2014 - ANR-14-CE05-0003 - Appel à projets générique - VALID, and Coherent diffrAction foR a look Inside Nanostructures towards atomic rEsolution: catalysis and interface - CARINE - 818823 - INCOMING

Subjects
[CHIM.CATA] Chemical Sciences/Catalysis, [CHIM.CATA]Chemical Sciences/Catalysis
Abstract

International audience; Due to strain and ligand effects, the simultaneous presence of concave and convex surfaces and their highly-defective nanostructure (atomic vacancies, grain boundaries), highly defective hollow PtNi/C electrocatalysts have proven to enhance remarkably the oxygen reduction reaction (ORR) kinetics [1,2]. Likewise, PtNi aerogel [3], jagged PtNi nanowires [4,5] feature both high concentration of structural defects and enhanced ORR activity. On the other hand, and inspired from single crystal approach, nanostructured octahedral-shaped PtNi/C electrocatalysts exhibiting only Pt(111) facets are among the most active ORR electrocatalysts [6,7]. This presentation will show how structure-activity-stability relationships of these two classes of materials can be unified via two descriptors derived from structural and electrochemical parameters respectively [8,9]. A special emphasis will be given on the stability trends of these two families of ORR electrocatalysts.

Published
2022

26. Crystallography in France, a selective instant view

Author

Bordet, Pierre, van Der Lee, Arie, Timmins, Joanna, Balan, Etienne, Cabaret, Delphine, Guinebretière, René, Velázquez, Matias, Guionneau, Philippe, Matériaux, Rayonnements, Structure (NEEL - MRS), 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), Association Française de Cristallographie, Institut Européen des membranes (IEM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), Institut de biologie structurale (IBS - UMR 5075), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les CERamiques (IRCER), Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), and Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.MATE]Chemical Sciences/Material chemistry
Abstract

Special Report; International audience; Academic scientific research in France is based around 70 universities, each with numerous departments, sites and branches, as well as around major research organisations. These include not only the Centre National de la Recherche Scientifique (CNRS), recognised as the second most important research institution in the world (Scimago Institutions Rankings), but also the Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA) and the Institut National de la Santé et de la Recherche Médicale (INSERM). In this context, and given the multidisciplinary nature of crystallography, it would appear complex, if not impossible, to draw up a complete and exhaustive overview of the activity of this science in France. This is not the purpose of this article. Nor is it the purpose of this article to relate the importance of the past activities of French researchers in crystallography. We will therefore not talk about Auguste Bravais, Georges Friedel, René Just Haüy or Charles Mauguin, nor about Louis Pasteur or the French crystallographers who were President of the IUCr such as André Guinier, Jean Wyart and André Authier. That is another story. The purpose of this opus is to illustrate the current status and dynamics of crystallography in France by focusing on a few major facts. By definition, the result is partial and probably also unintentionally biased. May the reader excuse us for this. However, despite the inherent flaws of the exercise, an initial mapping of our science in France is sketched out and testifies to a certain dynamism and a swarming of ideas and results, fruits of the hard work of so many colleagues. The purpose of this article is to pay tribute to them as France is preparing to host major crystallographic events in 2022: the 3rd European School and the 7th European Conference on Crystal Growth, July 2022, Paris; the 23rd General Meeting of the International Mineralogical Association, July 2022, Lyon; and the 33rd European Crystallography Meeting, August 2022, Versailles.

Published
2022

31. Cyclic Solid‐State Multiple Phase Changes with Tuned Photoemission in a Gold Thiolate Coordination Polymer

Author

Veselska, Oleksandra, primary, Vaidya, Shefali, additional, Das, Chinmoy, additional, Guillou, Nathalie, additional, Bordet, Pierre, additional, Fateeva, Alexandra, additional, Toche, François, additional, Chiriac, Rodica, additional, Ledoux, Gilles, additional, Wuttke, Stefan, additional, Horike, Satoshi, additional, and Demessence, Aude, additional

Published
2022
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33. Transparent and luminescent glasses of gold thiolate coordination polymers† †Electronic supplementary information (ESI) available: Chemicals, experimental details, and transmittance, PXRD, PDF, FT-IR, TGA, DSC, TMA, photoluminescence analysis and XANES results. See DOI: 10.1039/d0sc02258f

Author

Vaidya, Shefali, Veselska, Oleksandra, Zhadan, Antonii, Diaz-Lopez, Maria, Joly, Yves, Bordet, Pierre, Guillou, Nathalie, Dujardin, Christophe, Ledoux, Gilles, Toche, François, Chiriac, Rodica, Fateeva, Alexandra, Horike, Satoshi, and Demessence, Aude

Subjects
Chemistry
Abstract

Low mechanical pressure on amorphous gold thiolate coordination polymers allows the formation of transparent and red emissive glasses., Obtaining transparent glasses made of functional coordination polymers (CPs) represents a tremendous opportunity for optical applications. In this context, the first transparent and red-emissive glasses of gold thiolate CPs have been obtained by simply applying mechanical pressure to amorphous powders of CPs. The three gold-based CP glasses are composed of either thiophenolate [Au(SPh)]n, phenylmethanethiolate [Au(SMePh)]n or phenylethanethiolate [Au(SEtPh)]n. The presence of a longer alkyl chain between the thiolate and the phenyl ring led to the formation of glass with higher transparency. The glass transitions, measured by thermomechanical analysis (TMA), occurred at lower temperature for CPs with longer alkyl chains. In addition, all three gold thiolate glasses exhibit red emission at 93 K and one of them, [Au(SMePh)]n, remains luminescent even at room temperature. An in-depth structural study of the amorphous gold thiolates by XRD, PDF and EXAFS analysis showed that they are formed of disordered doubly interpenetrated helical chains. These d10 metal-based compounds represent the first examples of transparent and luminescent CP glasses.

Published
2020

35. Jeunes et violences

Author

Nikos Precas, William Gasparini, Fatou Dame Loum, Joëlle Bordet, Pierre Coupiat, Hugues Lagrange and Nikos Precas, William Gasparini, Fatou Dame Loum, Joëlle Bordet, Pierre Coupiat, Hugues Lagrange

Published
2005

36. Li trapping in nanolayers of cation 'disordered' rock salt cathodes.

Author

Diaz-Lopez, Maria, Chater, Philip A., Proux, Olivier, Joly, Yves, Hazemann, Jean-Louis, Bordet, Pierre, and Pralong, Valerie

Abstract

Disordered rock salt (DRS) cathodes have attracted considerable attention because of their high first charge capacities and relatively low cost. Here we investigate operando the structure and charge evolution of the Li1.1Mn0.7Ti0.2O2 Li-excess rock salt cathode with a first charge capacity of 270 mA h g−1. We associate a certain extent of the capacity fade in DRS to the in situ formation of locally ordered layered nanodomains during the electrochemical cycling of the long-range cation disordered rock salt. We quantify the short-range ordering of cations during cycling and evaluate its effect on the lithium-ion diffusion and charge compensation using operando studies based on X-ray total scattering and advanced spectroscopic methods at the Mn K-edge, namely high energy resolution fluorescence detected XANES and emission spectroscopies including main and valence-to-core transitions. [ABSTRACT FROM AUTHOR]

Published
2022
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37. A new Al-rich hydroxylian pseudorutile from Kalimantan, Indonesia

Author

Grey, Ian E., Bordet, Pierre, Wilson, Nicholas C., townend, Raimunda, Bastow, Timothy J., and Brunelli, Michela

Subjects
Diaspore -- Properties, Aluminum -- Properties, Crystals -- Structure, Crystals -- Observations, X-rays -- Diffraction, X-rays -- Methods, Earth sciences
Abstract

A new type of Al-rich hydroxylian pseudortuile (HPR), containing 64.6 wt% Ti[O.sub.2], 12.1 wt% [Al.sub.2][O.sub.3], 10.9 wt% [Fe.sub.2][O.sub.3], and 12.4 wt% [H.sub.2]O, has been identified in detrital heavy mineral concentrates from Central Kalimantan, Indonesia. The unusual translucent orange-colored grains have been characterized using electron microprobe analyses, thermal analyses, [sup.27]Al MAS NMR, and synchrotron XRD studies including the use of differential pair distribution function analysis, to determine how the Al is incorporated. The results support a model in which diaspore-form AIOOH is incorporated into nanopores in the solid hydrogel-like mineral. The HPR matrix structure comprises disordered unit-cell scale intergrowths of diaspore-type and rutile-type structure elements, which have a close dimensional match to the diaspore structure, thus providing a suitable template for epitactic nucleation and growth of the diaspore. The average composition of the grains is [Fe[Ti.sub.6][O.sub.10.8][(OH).sub.5.4]] x 1.8A1OOH x [H.sub.2]O, where the formula within the square brackets represents the HPR matrix, and the A1OOH and [H.sub.2]O occupy the intragrain pore volume. Keywords: Hydroxylian pseudorutile, Al-rich pseudorutile, synchrotron XRD study, diaspore-rutile intergrowth structure DOI: 10.2138/am.2010.3330

Published
2010
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38. Sustainable and Efficient Low‐Energy Light Emitters: A Series of One‐Dimensional d10 Coinage Metal–Organic Chalcogenolates, [M(o‐SPhCO2H)]n.

Author

Veselska, Oleksandra, Guillou, Nathalie, Diaz‐Lopez, Maria, Bordet, Pierre, Ledoux, Gilles, Lebègue, Sébastien, Mesbah, Adel, Fateeva, Alexandra, and Demessence, Aude

Subjects
LIGHT emitting diodes, COINAGE, COORDINATION polymers, SALICYLATES, HEXAGONS, RAW materials
Abstract

A series of d10 coinage metal thiosalicylate coordination polymers (CPs) is reported. The 1D structures of the three CPs are formed by M3S3 fused hexagons for Cu and Ag compounds and interpenetrated helical chains for Au CP. Depending on the metal, solid‐state red and NIR emissive CPs are obtained with quantum yields up to 50 %, providing a great opportunity to replace the actual emissive critical raw materials. [ABSTRACT FROM AUTHOR]

Published
2022
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40. Successive incommensurate spin orderings and excitations in multiferroic SrMnGe 2 O 6

Author

Colin, Claire, Ding, Lei, Ressouche, E., Robert, Julien, Terada, Noriki, Gay, Frederic, Lejay, Pascal, Simonet, Virginie, Darie, Céline, Bordet, Pierre, Petit, Sylvain, Matériaux, Rayonnements, Structure (MRS), 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), Magnétisme et Diffusion Neutronique (MDN ), 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Magnétisme et Supraconductivité (MagSup), National Institute for Materials Science (NIMS), Automatisation et Caractérisation (AUTOCARAC), Cristaux Massifs (CrisMass), LLB - Nouvelles frontières dans les matériaux quantiques (NFMQ), Laboratoire Léon Brillouin (LLB - UMR 12), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay

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

International audience; Anisotropic multiferroic properties of SrMnGe 2 O 6 pyroxene single crystals were systematically investigated by means of magnetization, heat capacity, pyroelectric current measurement and elastic and inelastic neutron scattering experiments. Single crystal neutron diffraction allows us to unambiguously

Published
2020

41. Incommensurate spin ordering and excitations in multiferroic SrMnGe2O6

Author

Colin, Claire, Ding, Lei, Ressouche, E., Robert, Julien, Terada, Noriki, Gay, Frederic, Lejay, Pascal, Simonet, Virginie, Darie, Céline, Bordet, Pierre, Petit, Sylvain, Matériaux, Rayonnements, Structure (NEEL - MRS), 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), Magnétisme et Diffusion Neutronique (MDN ), 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), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Magnétisme et Supraconductivité (NEEL - MagSup), National Institute for Materials Science (NIMS), Automatisation & caractérisation (NEEL - AUTOCARAC), Croissance Cristalline et MicroAnalyse (NEEL - C2MA), LLB - Nouvelles frontières dans les matériaux quantiques (NFMQ), Laboratoire Léon Brillouin (LLB - UMR 12), and 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)

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

International audience; Anisotropic multiferroic properties of SrMnGe 2 O 6 pyroxene single crystals were systematically investigated by means of magnetization, heat capacity, pyroelectric current measurement and elastic and inelastic neutron scattering experiments. Single crystal neutron diffraction allows us to unambiguously

Published
2020

45. Local structure studies using the pair distribution function

Author

Bordet Pierre

Subjects
Physics, QC1-999
Abstract

The pair distribution analysis method is a fast spreading structural analysis method allowing to go beyond classical crystallographic analysis by providing quantitative information about local as well as meso-structure. It based on powder diffraction data fourier transformed to direct space. We will present here the main characteristics of the method, and its domain of application.

Published
2015
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