Studies of X-Ray Induced Thermally Stimulated Luminescence of Cu~(2+)-Doped AeSO_4 (Ae = Ca, Ba, Sr and Mg) and Analysis of Kinetic Parameters by Using Glow-Curve Deconvolution Technique

摘要

Cu~(2+)-doped alkaline earth sulphates such as AeSO_4 (Ae = Ca, Ba, Sr and Mg) were synthesized via recrys-tallisation method and their thermally stimulated luminescence (TSL) characteristics have been investigated in the dose range of 0.05 to 1.5 Gy. Comparison of TSL intensity between the most intensive glow peaks of Cu-doped AeSO_4 compounds showed that addition of Cu impurity in CaSO_4 compound enhances the TL intensity many folds than the other samples. A significant aspect of these phosphors was their 'non-shifting T_m (peak temperature)' property when they were subjected to various doses of X-irradiation. Computerized glow curve deconvolution (CGCD) tool was effectively used to evaluate the effectual trapping parameters namely activation energy (E) and frequency factor (s) for the present samples. As received results indicated that the glow curve in the temperature region between room temperature and 400 ℃ could be described as a superposition of multiple peaks and suggested quasi-continuous distribution of traps with activation energy in the range of 0.26-2.6 eV for CaSO_4:Cu, 0.59-1.7 eV for BaSO_4:Cu, 0.37-1.37 for SrSO_4:Cu and 0.87-1.43 for MgSO_4:Cu. In order to verify the results, estimated from CGCD, the trap parameters coupled with the most intensive glow peaks of AeSO_4:Cu phosphors were also determined by using glow curve shape (Chen's) method.