Opto-electric and physio-chemical changes in oxygen ion irradiated natural Vermiculite mineral

Abstract

The influence of 80 MeV O6+ ion on Vermiculite mineral in terms of its optical, dielectric, structural, chemical, and thermoluminescence (TL) properties have been reported in this paper for the first time. The structural disorder was computed from Urbach energy using Cody model, and was applied to reveal the variation of optical band gap with ion fluence. The ac conductivity (σac) in both pristine and irradiated samples was found to obey Jonscher's power law. The mean crystallite size, micro strain and dislocation density were estimated from the analysis of X-Ray Diffraction pattern. The results of optical and dielectric parameters were found to be corroborated with structural changes of pristine and irradiated samples. FTIR spectroscopy of the samples reveals the broadening of bands and the decrease in overall intensity of the transmittance with the increase in ion fluence. Thermoluminescence studies were also performed to explore the dosimetric aspects of vermiculite. A prominent TL peak was observed around 148 °C to make Vermiculite a good dosimeter for eminent uses in radiation rich environs.