|
|||||
|
|
Silicon K-edge XANES spectra of silicate minerals |
|
| Authors: | Dien Li G M Bancroft M E Fleet X H Feng |
| Institution: | 1. Department of Chemistry, University of Western Ontario, N6A 5B7, London, Ontario, Canada 2. Department of Earth Sciences, University of Western Ontario, N6A 5B7, London, Ontario, Canada 3. Canadian Synchrotron Radiation, Synchrotron Radiation Center, University of Wisconsin, 53589, Stoughton, Wisconsin, USA |
| Abstract: | Silicon K-edge x-ray absorption near-edge structure (XANES) spectra of a selection of silicate and aluminosilicate minerals have been measured using synchrotron radiation (SR). The spectra are qualitatively interpreted based on MO calculation of the tetrahedral SiO 4 4? cluster. The Si K-edge generally shifts to higher energy with increased polymerization of silicates by about 1.3 eV, but with considerable overlap for silicates of different polymerization types. The substitution of Al for Si shifts the Si K-edge to lower energy. The chemical shift of Si K-edge is also sensitive to cations in more distant atom shells; for example, the Si K-edge shifts to lower energy with the substitution of Al for Mg in octahedral sites. The shifts of the Si K-edge show weak correlation with average Si-O bond distance (dSi-O), Si-O bond valence (sSi-O) and distortion of SiO4 tetrahedra, due to the crystal structure complexity of silicate minerals and multiple factors effecting the x-ray absorption processes. |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ | |