Photoluminescence investigations of rare earth (Eu and Gd) incorporated nuclear waste glass

Rare earth ion (Eu and Gd) bearing sodium–barium borosilicate glasses, used for vitrification of Trombay research rector nuclear waste were characterized by photoluminescence (PL) technique. This was done in order to identify the oxidation states and the coordination geometries of the ions in the glass matrix. It was observed that both the RE ions were stabilized in their 3+ oxidation state in an asymmetric geometry. Spectral analysis of the Eu-glass was carried out to evaluate the J–O intensity parameters and various radiative properties such as radiative transition rate (AR), radiative and non-radiative lifetimes (τR and τNR) and luminescence branching ratio (βR). These properties suggested that amount of covalence existing between the rare earth ions and surrounding oxygens is relatively higher and there is existence of short range ordering in the glass.