Thermal quenching in calcite and evaluation of quenching parameters from composite glow curve by a computerized resolved peak technique

Thermoluminescence (TL) glow curves of X-ray irradiated micro-grain calcite mineral were recorded at various heating rates (2, 4, 6, 8 and 10 K/s) under same linear temperature profile from 300 to 520 K. By using a Computerized Glow Curve Deconvolution technique, all composite glow curves of calcite were analyzed and the glow curves were found to be a combination of three distinct overlapping peaks. Activation energies corresponding to these three peaks were found to be 0.70, 0.60 and 1.30 eV respectively. For each set of computerized resolved peak, variation of peak maximum temperature, FWHM and peak area with heating rate were studied. Entire glow curves were found to be influenced by thermal quenching. Thermal quenching activation energy, W and the pre-exponential unitless constant, C were evaluated from each resolved peak individually. Thermal quenching activation energies for the three peaks were found to be 1.36±0.54, 1.14±0.73 and 1.38±0.40 eV respectively. The significance of determining the individual value of quenching parameters related to each peak for a composite glow curve is reported.