X-ray and Neutron Study on the Structure of Hydrous SiO2 Glass up to 10 GPa

Autor: Satoru Urakawa, Toru Inoue, Takanori Hattori, Asami Sano-Furukawa, Shinji Kohara, Daisuke Wakabayashi, Tomoko Sato, Nobumasa Funamori, Ken-ichi Funakoshi
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Minerals, Vol 10, Iss 1, p 84 (2020)
Druh dokumentu: article
ISSN: 2075-163X
10010084
DOI: 10.3390/min10010084
Popis: The structure of hydrous amorphous SiO2 is fundamental in order to investigate the effects of water on the physicochemical properties of oxide glasses and magma. The hydrous SiO2 glass with 13 wt.% D2O was synthesized under high-pressure and high-temperature conditions and its structure was investigated by small angle X-ray scattering, X-ray diffraction, and neutron diffraction experiments at pressures of up to 10 GPa and room temperature. This hydrous glass is separated into two phases: a major phase rich in SiO2 and a minor phase rich in D2O molecules distributed as small domains with dimensions of less than 100 Å. Medium-range order of the hydrous glass shrinks compared to the anhydrous SiO2 glass by disruption of SiO4 linkage due to the formation of Si−OD deuterioxyl, while the response of its structure to pressure is almost the same as that of the anhydrous SiO2 glass. Most of D2O molecules are in the small domains and hardly penetrate into the void space in the ring consisting of SiO4 tetrahedra.
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