THEORETICAL-ANALYSIS OF SI AND O XANES SPECTRA OF ZIRCON VS ALPHA-QUARTZ

Full multiple-scattering (MS) calculations of the X-ray absorption spe ctra at the silicon L(2,3), K and oxygen K-edges in zircon and alpha-q uartz and comparison to ELNES and XANES experimental data are used to elucidate the fine structure in the spectra. The pronounced difference s between the quartz vs zircon spectra are mostly in the intensities o f the transitions, not in their energies but can be fully modelled wit h the MS approach. It is shown that the intensities are related to the different site symmetries in these structures. Copyright (C) 1996 Els evier Science Ltd