Thermoluminescence of α-Al₂O₃:C,Mg: Kinetic analysis of the main glow peak

The kinetic analysis of the thermoluminescence of aluminium oxide doped with carbon and co-doped with magnesium (α-Al₂O₃:C,Mg) is reported. Measurements were made at 1 °C/s following beta irradiation to 1 Gy. The glow curve consists of a dominant peak at a peak-maximum T_m of 161 °C and six secondary peaks of weaker intensity at 42, 72, 193, 279, 330 and 370 °C. Kinetic analysis of the main peak, the subject of this report, was carried out using initial rise, whole glow peak, peak shape, curve fitting and variable heating rate methods. The order of kinetics of the main peak was determined as first order using various methods including the T_m–T_stop technique and the dependence of T_m on irradiation dose. The activation energy of the peak is about ~1.36 eV and the frequency factor of the order of 10¹⁴ s⁻¹. The peak area changes with heating rate in a manner that shows that the peak is affected by thermal quenching. The activation energy of thermal quenching was evaluated as 0.99±0.08 eV. A comparison of analytical results from the main peak before and after correction for thermal quenching show that the kinetic parameters of the main peak are not that affected by thermal quenching.