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(116) Production(s) de LEVELUT C.
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Topologically ordered amorphous silica obtained by pressure induced
amorphisation of silicalite
Auteur(s): Levelut C., Haines Julien, Isambert Aude, Hébert Philippe, Kohara Shinji, Keen David, Hammouda Tahar, Andrault Denis
Conference: 11th International Confrence on the structure of Non-crystalline Materials (paris, FR, 2010-06-28)
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Brillouin spectroscopy, calculated elastic and bond properties of GaAsO4. 
Auteur(s): Bhalérao Gopalkrishna, Cambon Olivier , Haines Julien, Levelut C., Mermet A., Sirotkin Sergey, Menaert Bertrand, Debray Jérôme, Baraille I., Darrigan Clovis, Rérat Michel
(Article) Publié:
Inorganic Chemistry, vol. 49 p.9470–9478 (2010)
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Silicon carbonate phase formed from carbon dioxide and silica under pressure
Auteur(s): Santoro Mario, Gorelli Federico, Haines Julien, Cambon Olivier, Levelut C., Garbarino Gastón
(Article) Publié:
Proceedings Of The National Academy Of Sciences Of The United States Of America, vol. 108 p.7689-7692 (2011)
Texte intégral en Openaccess : 
Ref HAL: hal-00634481_v1
PMID 21518903
DOI: 10.1073/pnas.1019691108
WoS: 000290439500016
Exporter : BibTex | endNote
58 Citations
Résumé: The discovery of nonmolecular carbon dioxide under high-pressure conditions shows that there are remarkable analogies between this important substance and other group IV oxides. A natural and long-standing question is whether compounds between CO2 and SiO2 are possible. Under ambient conditions, CO2 and SiO2 are thermodynamically stable and do not react with each other. We show that reactions occur at high pressures indicating that silica can behave in a manner similar to ionic metal oxides that form carbonates at room pressure. A silicon carbonate phase was synthesized by reacting silicalite, a microporous SiO2 zeolite, and molecular CO2 that fills the pores, in diamond anvil cells at 18-26 GPa and 600-980 K; the compound was then temperature quenched. The material was characterized by Raman and IR spectroscopy, and synchrotron X-ray diffraction. The experiments reveal unique oxide chemistry at high pressures and the potential for synthesis of a class of previously uncharacterized materials. There are also potential implications for CO2 segregation in planetary interiors and for CO2 storage.
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Deactivation of Pressure-Induced Amorphization in Silicalite SiO2 by Insertion of Guest Species
Auteur(s): Haines Julien, Cambon Olivier, Levelut C., Santoro Mario, Gorelli Federico, Gabarino Gaston
(Article) Publié:
Journal Of The American Chemical Society, vol. 132 p.8860–8861 (2010)
Ref HAL: hal-00498156_v1
PMID 20540493
DOI: 10.1021/ja1034599
WoS: 000279561200023
Exporter : BibTex | endNote
78 Citations
Résumé: The incorporation of carbon dioxide or argon stabilizes the structure of the microporous silica polymorph silicalite well beyond the stability range of tetrahedrally coordinated SiO2 and, in fact, beyond even the metastability range of low-pressure silica polymorphs such as quartz and cristobalite at room temperature. The bulk modulus of silicalite strongly increases as a result of the incorporation of CO2 or Ar and is equivalent to that of quartz. The insertion of these species deactivates the normal compression and pressure-induced amorphization mechanisms in this material, impeding the softening of low-energy vibrations, amorphization, and the eventual increase in silicon coordination up to at least 25 GPa.
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Anharmonicity and acoustical phonons in glasses
Auteur(s): Levelut C.
Conférence invité: 6th International discussion meeting on relaxations in complex (Rome, IT, 2009-08-30)
Résumé: Résumé (à complèter)
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X-Ray absorption spectroscopy: a powerful tool to probe the Zr shift towards the centrosymmetric position in PZT (PbZr(0.52)Ti(0.48)O3) under high pressure and high temperature C. Levelut",
Auteur(s): Levelut C.
Conference: 25 th european crystallographic (Istambul, TR, 2009-08-16)
Résumé: Résumé (à complèter)
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Initial structure memory of pressure-induced transformations in the phase-change
memory alloy Ge$_2$Sb$_2$Te$_5$
Auteur(s): Levelut C., Krbal Milos, Kolobov Alex, Le Parc R., Fons Paul, Hanfland Michael, Pradel Annie, Ribes Michel, Tominaga J.
Conference: 47th EHPRG (European High Pressure Group) Conference (paris, FR, 2009-09-06)
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