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.