Local Structures around Si, Al and Na in Hydrated Silicate Glasses
- USM 201 'Mineralogie-Petrologie', Museum National d'Histoire Naturelle, CNRS UMR 7160, Paris (France)
- Laboratoire des Geomateriaux, Universite de Marne la Vallee, Marne la Vallee (France)
- Institut fuer Geowissenschaften, Universitaet Potsdam (Germany)
- CNRS-UR1 SOLEIL, Gif sur Yvette, (France)
- Switzerland
XANES spectra were collected at the Si-, Al-, and Na K-edge in hydrous silicate glasses to understand the effect of water on the local structure around these cations. Around network forming Si and Al, no drastic changes are observed. Around Na, the dissolution of water creates more ordered environments in Al-bearing glasses and less ordered environment in Al-free glasses. Ab-initio XANES calculations were undertaken to understand the structural origins for these features. Based on these results, a bond valence model was refined that considers not only the present XANES experiments and models but also NMR information. The double percolation model refined explains, among others, the explosive properties of water-bearing hydrous melts, at the origin of a number of cataclysmic eruptions in subduction zones.
- OSTI ID:
- 21054598
- Journal Information:
- AIP Conference Proceedings, Vol. 882, Issue 1; Conference: XAFS13: 13. international conference on X-ray absorption fine structure, Stanford, CA (United States), 9-14 Jul 2006; Other Information: DOI: 10.1063/1.2644478; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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