The Silicon Environment in Silica Polymorphs, Aluminosilicate Crystals and Melts: An In Situ High Temperature XAS Study

L. Cormier (1) , D. R. Neuville (2) , J. Roux (2) , D. de Ligny , G. S. Henderson , A. -M. Flank (3) , P. Lagarde (3)

1 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
2 IPGP - Institut de Physique du Globe de Paris
3 SSOLEIL - Synchrotron SOLEIL

High temperature X-ray absorption spectroscopy at the Si K-edge has been used to obtain in situ information on SiO₂ phase transitions upon heating. Important modifications are observed for the XANES spectra of the high temperature polymorphs, in relation to disordering of the SiO₄ tetrahedra beyond the short-range correlations. This paper also presents the XANES spectra of anorthite (CaAl₂Si₂O₈) from room temperature up to the melt (1900 K). This study shows the possibilities for determining the Si environment in crystals and glasses up to the liquid state using in situ XANES measurements.

Keywords: 61.10.Ht; 61.43.Fs; 61.20.-p; X-ray absorption spectroscopy: EXAFS NEXAFS XANES etc.; Glasses; Structure of liquids

Domains: Sciences of the Universe [physics]

L. Cormier, D. R. Neuville, J. Roux, D. de Ligny, G. S. Henderson, et al.. The Silicon Environment in Silica Polymorphs, Aluminosilicate Crystals and Melts: An In Situ High Temperature XAS Study. X-Ray Absorption Fine Structure - XAFS13: 13th International Conference. Proceedings held at Stanford, 0000, à renseigner, Unknown Region. pp.416-418, ⟨10.1063/1.2644544⟩. ⟨insu-03603197⟩