Study Some of Optical and Thermoluminescence Properties of Muscovite Mica Exposed to Ultraviolet Radiation

Abstract

Thermoluminescence properties of ultraviolet-irradiated muscovite sample from Egypt have been studied. One TL peak is observed in the natural material around 190 14鈩?/m:t>"> . A linear response curve to ultraviolet radiation was obtained over the exposure time ranging from 15min to 75 min. A fading study over a period of 15 days shows that the UV-exposed aliquots faded by 27% when exposed for 150 min. The optical direct band gap decreased closely from 3.2eV to 3.1eV after irradiation which means improving crystallinity. Urbach energy decreased from 1.9eV to 1.8eV after irradiation shows less structural disorder. These results further indicate the potential of muscovite as a phosphor in retrospective dosimetry and TL dating.

Keywords: Muscovite, optical properties, thermoluminescence properties,ultraviolet-irradiation.