Anomalous dose behaviour of thermoluminescence glow curves and kinetic analysis of beta irradiated YAl(BO):Tb phosphor.

With the aid of thermoluminescence (TL), we have extensively studied YAl(BO) host matrices incorporated with Tb at different doping contents, which have been produced by combustion. The measured the TL glow curves exposed to beta rays at different doses consisted of four broad peaks located at around 76, 126, 230, and 378 °C. The peak maximum of the 230 °C TL peak shifts toward higher temperatures after 5 Gy beta irradiation while the other peak maxima almost remain constant. It is peculiar that 230 °C peak maximum shifts to higher temperatures with increased radiation dose and can be attributed to the multiple phases of the sample. A TL glow curve exhibits a proportional increase in intensity with increased the heating rate. A discussion of the possible causes of this pattern is provided. Observed peaks using the T─T method are due to the presence of a quasi-continuous distribution of traps. The parameters of the traps have also been estimated using various heating rate methods in excellent agreement with one another.