Structural evaluation and shielding behavior of gamma irradiated vanadium doped silicophosphate glasses

Abstract

Ultraviolet and visible spectroscopic studies of base undoped and V2O5-doped sodium silicophosphate glasses were carried out in order to characterize the valence states of vanadium ions in such host mixed glass forming oxides. The same spectroscopic measurements were repeated after subjecting the glass to gamma irradiation with a dose of 8Mrad (8×104Gy). The base glass without V2O5 reveals an UV absorption band which is related to the presence of unavoidable trace iron impurities within the chemicals used for the preparation of this glass. V2O5-doped glasses exhibit extended UV–visible absorption spectra which are attributed to the collective presence of vanadium ions in three possible valencies V3+, V4+ and V5+ with the lower valence predominating.Infrared absorption spectra of the prepared samples indicate the combined presence of vibrational bands due to the sharing of both phosphate and silicate networks in the IR spectra. The addition of V2O5 in the doping level (0.1–3%) did not cause obvious changes in the IR spectra. Gamma irradiation produces noticeable but limited UV–visible spectral variations which show some shielding behavior in some cases. X-ray diffraction technique was applied to confirm the amorphous nature of the prepared glasses. ESR spectral data confirm the optical spectra results indicating the presence of both V3+ and V4+ ions in measurable percent.