Kinetic Analysis of Thermoluminescence Glow Curve of Indian Sillimanite

In the present work thermoluminescence (TL) properties of natural sillimanite mineral has been studied after grounded it to powder form. Powder X-ray diffraction analysis shows the crystalline nature of the sample. TL measurement from the un-irradiate sample results no signal, but after 60 mGy X-ray dose irradiation a high intensity glow peak (at ~360 K) followed by a low intensity peak (at ~424 K) have been observed in the glow curve. After annealing the sample at 473 and 773 K for 30 minutes, some deformations in the peaks of the glow curve have been observed. The Glow Curve De-convolution analysis reveals that the glow curve of un-annealed sample is practically a combination of four closely spaced TL peaks located at around 330, 362, 388 and 424 K. However after annealing, the lowest temperature peak has not observed. Analysis shows that the lowest temperature peak in the un-annealed sample is due to a pressure induced surface trapping site developed during grinding and after annealing it disappears from the crystal.