Carbon enters silica forming a cristobalite-type CO2-SiO2 solid solution

Anno: 2014

Autori: Santoro M., Gorelli F. A., Bini R., Salamat A., Garbarino G., Levelut C., Cambon O., Haines J.

Affiliazione autori: CNR, INO, Ist Nazl Ott, I-50019 Sesto Fiorentino, Italy; European Lab Nonlinear Spect LENS, I-50019 Sesto Fiorentino, Italy; Univ Florence, Dipartimento Chim, I-50019 Sesto Fiorentino, Italy; European Synchrotron Radiat Facil, F-38043 Grenoble 9, France; Univ Montpellier 2, Dept Colloides Verres & Nanomat CVN, CNRS, Lab Charles Coulomb,UMR 5221, F-34095 Montpellier 5, France; Univ Montpellier 2, Equipe C2M, CNRS, Inst Charles Gerhardt Montpellier,UMR 5253, F-34095 Montpellier 5, France

Abstract: Extreme conditions permit unique materials to be synthesized and can significantly update our view of the periodic table. In the case of group IV elements, carbon was always considered to be distinct with respect to its heavier homologues in forming oxides. Here we report the synthesis of a crystalline CO2-SiO2 solid solution by reacting carbon dioxide and silica in a laser-heated diamond anvil cell (P = 16-22 GPa, T>4,000 K), showing that carbon enters silica. Remarkably, this material is recovered to ambient conditions. X-ray diffraction shows that the crystal adopts a densely packed alpha-cristobalite structure (P4(1)2(1)2) with carbon and silicon in fourfold coordination to oxygen at pressures where silica normally adopts a sixfold coordinated rutile-type stishovite structure. An average formula of C0.6(1)Si0.4(1)O2 is consistent with X-ray diffraction and Raman spectroscopy results. These findings may modify our view on oxide chemistry, which is of great interest for materials science, as well as Earth and planetary sciences.


Volume: 5      Da Pagina: 3761  A: 3761

Maggiori informazioni: We acknowledge the ESRF for provision of beam time at ID27 and M. Mezouar (ESRF), J.A. Montoya (University of Cartagena, Colombia) and S. Scandolo (International Centre for Theoretical Physics (ICTP), Trieste, Italy) for very useful discussions. We also thank the support from the European Union (European Laboratory for Non-Linear Spectroscopy (LENS) contract G.A. no. 284464 LASERLABEUROPE), the Ente Cassa di Risparmio di Firenze, the Deep Carbon Observatory initiative (Grant from the Alfred P. Sloan Foundation for the project entitled \’Physics and Chemistry of Carbon at Extreme Conditions\’), and the Agence Nationale de la Recherche (contract ANR-09-BLAN-0018-01). M.S. thanks the \’Pole Chimie Balard\’ of Montpellier for having supported his research as an Invited Professor at the Institut Charles Gerhardt in 2013 in the framework of the Total chair.
Parole chiavi: X ray diffraction; high pressure; Raman spectroscopy; CO2; SiO2
DOI: 10.1038/ncomms4761

Citazioni: 28
dati da “WEB OF SCIENCE” (of Thomson Reuters) aggiornati al: 2024-07-21
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