Synthesis and thermoluminescence study of Eu doped novel LaBO3 phosphor: Heating rate, dose response, trapping parameters

Abstract

In this study, LaBO3, one of the Lanthanum-based perovskites-type oxides, and a series of LaBO3:Eu3+ phosphor samples were synthesized by solid state reaction technique. By using XRD, samples of the synthesized samples were analysed to identify a compound that indicates orthorhombic cells belonging to the Pmcn (62) space group. After 5 Gy of beta irradiation, the sample doped with 0.5 mass % Eu showed the highest integrated thermoluminescence intensity (TL). To evaluate the dose response, samples were irradiated with beta radiation from 0.1 to 100 Gy. The studied sample exhibits linear behaviour up to doses up to 5 Gy, while above this (up to 100 Gy) shows quasi-linear behaviour before reaching saturation. The peak number, trap structure, and kinetic parameters of Eu-doped LaBO3 thermoluminescence curves were determined using an initial rise method combined with TM-Tstop experiments, various heating rates (VHR), and Glow Curve Deconvolution (GCD) method. TM–Tstop calculations suggest nine plateaus of activation with energies of 1.21 eV, 0.98 eV, 1.03 eV, 1.32 eV, 1.43 eV, 0.68 eV, 1.98 eV, 1.83 eV and 1.92 eV which constitute the main radiation storage contributions. The GCD method was used to calculate trap depths and frequency factors ranging from 0.68 to 1.95 eV and from 106 to 1015 s−1, respectively. In VHR method, one of the high temperature glow peaks exhibited unusual behaviour which was attributed to a competition between radiative and non-radiative transitions.