A series of titanium silicate glasses along the composition joins TiO2–SiO2, TiO2–Na2SiO3, TiO2–K2SiO3 and TiO2–CaSiO3, has been examined using oxygen K-edge X-ray absorption near edge structure spectroscopy (XANES) confined to the near-surface region. Sharp pre-edge features in the spectra can be used to determine the Ti coordination in the glasses. The presence of Ti is indicated by a pre-edge peak at ~534 eV while Ti is indicated by a peak at ~533 eV. Titanium exists in all these glasses as Ti and Ti with no Ti being present. For alkali-containing glasses the Ti site becomes more prevalent with increasing TiO2. TiO2-K2SiO3 compositions contain a greater proportion of Ti than comparable Na2O compositions. This is consistent with earlier Ti L-edge findings. The TEY spectra for the TiO2-CaSiO3 compositions indicate the presence of significant amounts of Ti at high TiO2 contents; however, comparison of TEY (near surface) and FY (bulk sample) XANES shows that the Ti is confined to the surface of the glass sample with the bulk of the glass containing Ti.
KEYWORDS: Ti, XANES, silicate glasses
G. S. Henderson1,*, Xiaoyang Liu2 and M. E. Fleet2
1 Department of Geology, University of Toronto, 22 Russell Street, Toronto, Ontario M5S 3B1, Canada
2 Department of Earth Sciences, University of Western Ontario, London, Ontario N6A 5B7, Canada
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