Trapping levels in KAlSi3O8

The complex thermally stimulated luminescence (TSL) pattern of microcline can be resolved into as many as six TSL peaks occuring in the regions of 70 to 80, 120 to 135, 175 to 190, 205 to 220, 270 to 285, and 320 to 340 °C. Fractional glow technique (FGT) analysis in the temperature range 40 to 270 °C reveals the existence of four discrete traps with depth of 0.75; 1.00; 1.12, and around 1.36 eV. The first three traps can be linked to the first three peaks while the 1.36 eV trap can be correlated to the fourth and fifth peaks. All the six peaks are analysed by the curve fitting method. In the case of orthoclase the peaks occur in the regions of 65 to 80, 135 to 150, 190 to 210, 280 to 310 and probably a weak peak in the region 350 to 360 °C. The main four peaks are analysed by FGT as well as by curve fitting method. All the TSL peaks in both the system follow second order kinetics. The excellent agreement of FGT results with those of the curve fitting method in determining the trap depth demonstrates the rich potentiality of FGT in analysis of complex TSL patterns. The frequency factor in all the cases lies between 109 to 1013 s−1 which establishes the physical significance of the glow curve results.