Room temperature X-ray and positron annihilation lifetime spectroscopic studies of cavansite Crystals

The positron annihilation lifetime spectroscopy (PALS) of cavansite crystals collected from Wagholi, Pune district of Western Maharastra, India were characterized by 60Co gamma radiation with an irradiation dose of 1 Mrad and 3 Mrad at ambient conditions. The influence of γ-irradiation on the pore size and its content on cavansite structure were examined. The studies suggest ortho-positronium (o-Ps) lifetime (τ 3) and intensity (I 3) decreased upon γ-irradiation. The decreased o-Ps lifetime (τ 3) is attributed to the collapse of the framework structure of cavansite crystal. In addition, the reduction in o-Ps intensity (I 3) is known to decrease o-Ps annihilation sites because of free radical reactions.