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3. The structure of near stoichiometric Ge-Ga-Sb-S glasses: a reverse Monte Carlo study

Author

Pethes, Ildikó, Nazabal, Virginie, Chahal, Radwan, Bureau, Bruno, Kaban, Ivan, Beuneu, Brigitte, Bednarcik, Jozef, and Jóvári, Pál

Subjects
Condensed Matter - Materials Science, Condensed Matter - Disordered Systems and Neural Networks, Physics - Chemical Physics
Abstract

The structure of Ge$_{22}$Ga$_3$Sb$_{10}$S$_{65}$ and Ge$_{15}$Ga$_{10}$Sb$_{10}$S$_{65}$ glasses was investigated by neutron diffraction (ND), X-ray diffraction (XRD), and extended X-ray absorption fine structure (EXAFS) measurements at the Ge, Ga and Sb K-edges. Experimental data sets were fitted simultaneously in the framework of the reverse Monte Carlo (RMC) simulation technique. Short range order parameters were determined from the obtained large-scale configurations. It was found that the coordination numbers of Ge, Sb and S are around the values predicted by the Mott-rule (4, 3 and 2, respectively). The Ga atoms have on average 4 nearest neighbors. The structure of these stoichiometric glasses can be described by the chemically ordered network model: Ge-S, Ga-S and Sb-S bonds are the most important. Long Sb-S distances (0.3 - 0.4 {\AA} higher than the usual covalent bond lengths) are observed, suggesting that Sb atoms can be found in various local environments., Comment: 27 pages, 7 figures

Published
2018
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4. Atomic level structure of Ge-Sb-S glasses: chemical short range order and long Sb-S bonds

Author

Pethes, Ildikó, Nazabal, Virginie, Ari, Julien, Kaban, Ivan, Darpentigny, Jacques, Welter, Edmund, Gutowski, Olof, Bureau, Bruno, Messaddeq, Younès, and Jóvári, Pál

Subjects
Condensed Matter - Disordered Systems and Neural Networks, Physics - Chemical Physics
Abstract

The structure of Ge$_{20}$Sb$_{10}$S$_{70}$, Ge$_{23}$Sb$_{12}$S$_{65}$ and Ge$_{26}$Sb$_{13}$S$_{61}$ glasses was investigated by neutron diffraction (ND), X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS) measurements at the Ge and Sb K-edges as well as Raman scattering. For each composition, large scale structural models were obtained by fitting simultaneously diffraction and EXAFS data sets in the framework of the reverse Monte Carlo (RMC) simulation technique. Ge and S atoms have 4 and 2 nearest neighbors, respectively. The structure of these glasses can be described by the chemically ordered network model: Ge-S and Sb-S bonds are always preferred. These two bond types adequately describe the structure of the stoichiometric glass while S-S bonds can also be found in the S-rich composition. Raman scattering data show the presence of Ge-Ge, Ge-Sb and Sb-Sb bonds in the S-deficient glass but only Ge-Sb bonds are needed to fit diffraction and EXAFS datasets. A significant part of the Sb-S pairs has 0.3-0.4 {\AA} longer bond distance than the usually accepted covalent bond length (~2.45 {\AA}). From this observation it was inferred that a part of Sb atoms have more than 3 S neighbors., Comment: 23 pages, 6 figures, submitted to Journal of Alloys and Compounds

Published
2018
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7. Local motifs in GeS$_2$-Ga$_2$S$_3$ glasses

Author

Pethes, Ildikó, Nazabal, Virginie, Chahal, Radwan, Bureau, Bruno, Kaban, Ivan, Belin, Stéphanie, and Jóvári, Pál

Subjects
Condensed Matter - Disordered Systems and Neural Networks, Condensed Matter - Materials Science
Abstract

The structure of (GeS$_2$)$_{0.75}$(Ga$_2$S$_3$)$_{0.25}$ and (GeS$_2$)$_{0.83}$(Ga$_2$S$_3$)$_{0.17}$ glasses was investigated by Raman scattering, high energy X-ray diffraction and extended X-ray absorption fine structure (EXAFS) measurements at the Ga and Ge K-edges. The reverse Monte Carlo simulation technique (RMC) was used to obtain structural models compatible with diffraction and EXAFS datasets. It was found that the coordination number of Ga is close to four. While Ge atoms have only S neighbors, Ga binds to S as well as to Ga atoms showing a violation of chemical ordering in GeS$_2$-Ga$_2$S$_3$ glasses. Analysis of the corner- and edge-sharing between [GeS$_{4/2}$] units revealed that about 30% of germanium atoms participate in the edge-shared tetrahedra., Comment: 23 pages, 7 figures, accepted for publication in Journal of Alloys and Compounds

Published
2016
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10. Chalcogenide Glasses

Author

Zhang, Xiang-Hua, Adam, Jean-Luc, Bureau, Bruno, Musgraves, J. David, editor, Hu, Juejun, editor, and Calvez, Laurent, editor

Published
2019
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11. Free-Volume Structure of Polyvinylpyrrolidone-Capped Glassy [As.sub.2][Se.sub.3] Nanocomposites Prepared by Mechanical Milling

Author

Shpotyuk, Oleh, Ingram, Adam, Bujnakova, Zdenka, Balaz, Peter, Shpotyuk, Yaroslav, Slobodzyan, Dmytro, Wozny, Mariusz, Boussard-Pledel, Catherine, and Bureau, Bruno

Subjects
Povidone, Algorithms, Spectroscopy, Formalism (Literary criticism), Engineering and manufacturing industries, Science and technology
Abstract

The method of positron annihilation lifetime (PAL) spectroscopy was first employed to study atomic-deficient free-volume structure of nanocomposites prepared by high-energy mechanical milling of glassy g-[As.sub.2][Se.sub.3] in water solution of polyvinylpyrrolidone (PVP). The formalism of x3-x2-CDA (coupling decomposition algorithm) describing conversion of bound positron-electron (positronium Ps) states into positron traps was applied to identify free-volume elements in pelletized PVP-capped g-[As.sub.2][Se.sub.3] nanocomposite in respect to parent dry-milled g-[As.sub.2][Se.sub.3]. Under wet milling, the internanoparticle Ps-decaying sites in preferential PVP environment were shown to replace free-volume positron traps in dry-milled g-[As.sub.2][Se.sub.3] with defect-specific positron lifetime of 0.352 ns, corresponding to diatomic/triatomic vacancies in g-As-Se matrix., INTRODUCTION The chalcogenide compounds represented by arsenic trisulfide [As.sub.2][S.sub.3], different monosulfide [As.sub.4][S.sub.4] polymorphs, and arsenolite [As.sub.2][O.sub.3], known as arsenicals [1], have attracted a tight interest in biomedicine because of their [...]

Published
2019
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14. Nonoxide Tellurium-Based Glasses

Author

Hubert, Mathieu, Boussard-Plédel, Catherine, Bureau, Bruno, Lucas, Pierre, Hull, Robert, Series editor, Rivera, V.A.G., editor, and Manzani, Danilo, editor

Published
2017
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31. Extended aging of Ge–Se glasses below the glass transition temperature.

Author

King, Ellyn A., Sen, Sabyasachi, Takeda, Wataru, Boussard-Pledel, Catherine, Bureau, Bruno, Guin, Jean-Pierre, and Lucas, Pierre

Subjects
GERMANATE glasses, DIFFERENTIAL scanning calorimetry, RAMAN spectroscopy, CHARACTERISTIC functions, HEAT capacity, GLASS transition temperature
Abstract

Germanium selenide glasses of compositions spanning the whole glass-formation range are aged at room temperature for up to 20 years. A prominent enthalpy relaxation process is observed in all glasses, and its structural origin is analyzed by Raman spectroscopy. The structural relaxation is manifested in the Raman spectra as a decrease in the ratio of edge- to corner-sharing GeSe4/2 tetrahedral units. This structural evolution can be explained in terms of configurational entropy and density changes. Changes in Raman features and enthalpy follow an identical stretched exponential relaxation function characteristic of aging in glasses. The compositional dependence of enthalpy relaxation after 20 years is in agreement with kinetic considerations based on the glass transition temperature of each glass. The relaxation behavior and heat capacity curves are consistent with standard glass relaxation models for all compositions. These results indicate that the non-reversing enthalpy obtained by modulated differential scanning calorimetry (MDSC), which suggests the existence of non-aging glasses, is not a reliable measure of the ability of a glass to relax. Instead, it is suggested that an interpretation of MDSC data in terms of complex heat capacity provides a more complete and reliable assessment of the relaxation properties of glasses. [ABSTRACT FROM AUTHOR]

Published
2021
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32. Figures de l’identité

Author

Baroin, Catherine, Baudry, Robinson, Blandenet, Maëlys, Bureau, Bruno, Charles-Laforge, Marie-Odile, Chillet, Clément, Courrier, Cyril, Ducos, Michèle, Durand, Christine, Glinatsis, Robin, Guilhembet, Jean-Pierre, Hermand, Laure, Jacotot, Mathieu, Kefallonitis, Stavroula, Kimmel, Flore, Laronde, André, Lefebvre, Laurie, Lévy, Johanne, Marius Martin, Paul, Passet, Laure, Raymond, Emmanuelle, Roman, Yves, Roux, Magalie, Suspène, Arnaud, Blandenet, Maëlys, Chillet, Clément, and Courrier, Cyril

Subjects
History, Rome, HB, Histoire antique, HIS000000, identité collective, condition sociale, Péninsule italienne
Abstract

Crise de l’identité collective, revendications communautaires, évolution des modèles sociopolitiques : autant de problématiques qui, malgré leur actualité et leur apparente modernité, constituaient déjà des défis majeurs dans l’Antiquité. Pour qui s’intéresse à la formation, à la transmission et à l’évolution des formes d’autoreprésentation collective, le monde romain offre défait un champ d’investigation privilégié, où les diverses communautés politiques, sociales ou littéraires n’ont eu de cesse d’interroger les fondements de leur identité en érigeant des figures modèles ou des contre-modèles. Fruit de réflexions menées pendant plusieurs années à l’ENS de Lyon par le laboratoire junior EMCA (Étude des modèles culturels dans l’Antiquité), cet ouvrage aborde la question de l’histoire des origines de la cité et des grands hommes du passé, des pratiques sociales de la vie quotidienne ou encore de la perception des différents genres poétiques. Patronné par André Laronde, il réunit les travaux de seize chercheurs, littéraires et historiens, qui, par ces regards croisés, lancent des éclairages nouveaux sur la question de l’identité collective dans le monde romain.

Published
2022

33. Identités brouillées : une réflexion sur l’appartenance romaine au début du ve siècle à partir d’un problème textuel

Author

Bureau, Bruno

Subjects
History, Rome, HB, Histoire antique, HIS000000, identité collective, condition sociale, Péninsule italienne
Abstract

Le début du ve siècle en Occident coïncide, comme chacun le sait, avec une période de troubles sans précédent où l’intégrité même de l’imperium Romanum est gravement menacée, à la fois par l’afflux de populations étrangères et par la division et l’impuissance du pouvoir romain. Il est donc aisément explicable que se pose avec une particulière acuité dans un certain nombre de textes de cette époque la question de savoir ce que c’est qu’être Romain et si au fond il est bien souhaitable d’appart...

Published
2022

34. Broadband Photosensitive Medium Based on Amorphous Equichalcogenides

Author

Golovchak, Roman, primary, Plummer, Jarres, additional, Kovalskiy, Andriy, additional, Holovchak, Yuriy, additional, Ignatova, Tetyana, additional, Nowlin, Kyle, additional, Trofe, Anthony, additional, Shpotyuk, Yaroslav, additional, Boussard-Pledel, Catherine, additional, and Bureau, Bruno, additional

Published
2022
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39. Towards chalcogenide platform infrared sensors dedicated to the in situ detection of aromatic hydrocarbons in natural waters via an attenuated total reflection spectroscopy study

Author

Baillieul, Marion, Baudet, Emeline, Michel, Karine, Moreau, Jonathan, Němec, Petr, Boukerma, Kada, Colas, Florent, Charrier, Joel, Bureau, Bruno, Rinnert, Emmanuel, Nazabal, Virginie, Baillieul, Marion, Baudet, Emeline, Michel, Karine, Moreau, Jonathan, Němec, Petr, Boukerma, Kada, Colas, Florent, Charrier, Joel, Bureau, Bruno, Rinnert, Emmanuel, and Nazabal, Virginie

Abstract

The goal of this study was to demonstrate the successful functionalization of the surface of a chalcogenide infrared waveguide with the ultimate objective of developing an infrared micro-sensor device., Cílem této studie bylo demonstrovat úspěšnou funkcionalizaci povrchu chalkogenidového vlnovodu pro infračervenou oblast s konečným záměrem vývoje mikrosenzorického zařízení pro infračervenou oblast spektra.

Published
2022

45. Structural and chemical homogeneity of chalcogenide glass prepared by melt-rocking.

Author

Lucas, Pierre, Coleman, Garrett J., Sen, Sabyasachi, Cui, Shuo, Guimond, Yann, Calvez, Laurent, Boussard-Pledel, Catherine, Bureau, Bruno, and Troles, Johann

Subjects
CHALCOGENIDE glass, HOMOGENEITY, ENERGY dispersive X-ray spectroscopy, GERMANIUM selenide, DIFFUSION coefficients
Abstract

The chemical and structural homogeneity of selenide glasses produced by mechanical homogenization of the melt in a rocking furnace is investigated by Raman and Energy Dispersive Spectroscopy (EDS). Both techniques demonstrate that the glass is macroscopically homogeneous along the entire length of a 6 cm rod. EDS imaging performed over four orders of magnitude in scale further confirms that the glass is homogeneous down to the sub-micron scale. An estimate of the diffusion coefficient from experimental viscosity data shows that the diffusion length is far larger than the resolution of EDS and therefore confirms that the glass is homogeneous at any length scale. In order to investigate a systematic mismatch in physical properties reported in the literature for glasses produced by extended static homogenization, two germanium selenide samples are produced under the same conditions except for the homogenization step: one in a rocking furnace for 10 h and the other in a static furnace for 192 h. No difference in physical properties is found between the two glasses. The properties of an ultra-high purity glass are also found to be identical. The origin of the systematic deviation reported in the literature for germanium selenide glasses is therefore still unknown, but the present results demonstrate that homogeneity or dryness does not have a significant contribution in contrast to previous suggestions. The implications of glass homogeneity for technological applications and industrial production are discussed. [ABSTRACT FROM AUTHOR]

Published
2019
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48. Les enjeux nouveaux qu’ouvrent les Humanités Numériques en lien avec les pratiques éditoriales traditionnelles et leur questionnement

Author

Bureau, Bruno

Subjects
General Engineering
Abstract

Bureau Bruno. Les enjeux nouveaux qu’ouvrent les Humanités Numériques en lien avec les pratiques éditoriales traditionnelles et leur questionnement. In: Bulletin de l'Association Guillaume Budé, n°1,2019. Éditer, traduire, annoter les textes au XXIes. Poursuivre la tradition humaniste. Actes du XVIIIè congrès de l’association Guillaume Budé. pp. 132-149.

Published
2019

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