EPR study of Ti3+ ions formed under beta irradiation in silicate glasses

Reduction processes of Ti4+ ions in various silicate glasses have been studied by EPR spectroscopy at 20 K. Different parameters like the [Na]/[Ti] ratio, the integrated dose and Ti3+ ions ageing processes were analyzed in this work. Simulation of the Ti3+ ion EPR spectra in different Ti-doped silicate glasses has shown three different Ti3+ environments attributed to one [VI]Ti3+ and two [V]Ti3+ environment (square pyramid and trigonal bi-pyramid). The [VI]Ti3+ ion environment is observed only for [Na]/[Ti] ratios higher or equal to 68 although the two others are observed for all values of the [Na]/[Ti] ratio considered. In terms of relative proportions, the Ti3+ ions in a square pyramid of oxygen are the dominant species. (authors)