Photoluminescence and scintillation properties of Tb-doped SrTa₂O₆ single crystals

Abstract

We fabricated 0.1, 0.3, 1.0, and 3.0 % Tb-doped SrTa₂O₆ single crystal samples using the floating zone method to evaluate their photoluminescence and scintillation properties. The XRD measurement results showed no impurity phases and retained a single-phase structure for all samples. In addition, no clear peak shift was observed, which was thought to be due to a small amount of Tb³⁺ substituted on the Sr²⁺ site or the substitution of Tb⁴⁺ with a close ionic radius on the Ta⁵⁺ site. The photoluminescence measurements of all the samples confirmed luminescence due to the 4f–4f transitions of Tb³⁺ ions at an excitation wavelength of 280 nm, and the maximum internal quantum yield of 25.5 % was observed in the 0.1 % sample. The scintillation spectra were obtained under X-ray irradiation, and several emission peaks were observed in all the samples, originating from 4f–4f transitions of Tb³⁺ ions. The maximum scintillation integral intensity was obtained in the 0.3 % sample, which was about 47 % of the values of BGO set to 100 %.