Synthesis and investigation of thermoluminescence properties of rare earth (Dy) doped CaAL4O7

In this study the thermoluminescence (TL) properties of calcium aluminate (CaAl4O7) doped with rare earth ion, Dysprosium (Dy), have been investigated in detail. CaAl4O7:Dy phosphors were synthesized by using the sol-gel method. The glow curves of the samples were evaluated by using 90Sr-90Y (≈ 0.04 Gy/s) beta source for different dose levels between 0.2 Gy and 864 Gy and the kinetic parameters such as activation energy (Ea), and order of kinetics (b) were calculated by using peak shape method, heating rate method, and computer glow curve deconvolution method. The results of the experiments have shown that the sample has two general order glow peaks; P1 at 125oC and P2 at 160 oC. The peak at 125oC has a kinetic order of b=1.5 and activation energy Ea= 0.5 eV. The fading characteristics of the sample were also studied over a period time. The samples were irradiated and stored in a darkroom at room temperature. The results have shown that, the intensity of the main glow peak (P1) of CaAl4O7: Dy at the end of the planned storage times reduced typically 51 % of its original value.