Thermoluminescence glow curves analysis of pure and CeO2-doped Li2O-Al2O3-SiO2 glass ceramics

摘要

A comparative study of the thermoluminescence (TL) emission between beta-irradiated lithium aluminosilicates, Li2O-Al2O3-SiO2 (LAS), and beta-irradiated CeO2-doped lithium aluminosilicates, Li2O-Al2O3-SiO2-CeO2 (LAS:Ce), grown by sol-gel technique and preannealed at 1250 degrees C is presented. It is found that doping reinforces the result of preannealing the sample: the incorporation of CeO2 at low concentrations shifts the TL curves towards higher temperatures and increases the total intensity with respect to samples without the dopant. This behavior, together with the fact that CeO2 is a good densification agent, suggests the possibility of using CeO2 to improve the technological properties of LAS. Deconvolution analysis of the thermoluminescence glow curves of doped materials under general order kinetics shows that the relevant temperatures at which the component signals appear are virtually the same as for pure samples. This suggests that CeO2 does not introduce new types of traps, but only changes the population and distribution of impurities responsible for the TL in the original matrix of LAS. Finally, the kinetic parameters for the deconvoluted curves are reported. They corroborate that changes in CeO2 concentration only vary the depth and distribution of the same kind of original traps.