Photoluminescence, thermally stimulated luminescence and electron paramagnetic resonance investigations of Tb3+ doped SrBPO5

Trap level spectroscopic studies were carried out on γ-irradiated Tb (1 mole%) doped SrBPO5 were carried out using photoluminescence (PL), thermally stimulated luminescence (TSL) and electron paramagnetic resonance (EPR) techniques. The incorporation of Tb in the 3+ oxidation state was ascertained from PL studies. Life time for Tb3+ emission corresponding to the intense transition 5D4 → 7F5 at 543 nm was determined. The spectral characteristics of the TSL glows have shown that Tb3+ ions act as the emission center for the glow peak at 475 K. The trap parameters of the glow peak were determined. EPR investigations at room temperature/77 K revealed the stabilization of three boron oxygen hole trapped centers (BOHCʹs) and oxygen centered radicals such as O− and O2− and trapped electrons in room temperature γ-irradiated samples. TSL glow peak at 475 K was found to be associated with recombination of electron released from trapped electron center and the BOHC2 center.