Optical and infrared spectral investigations of cadmium zinc phosphate glasses doped with WO3 or MoO3 before and after subjecting to gamma irradiation

Optical and FTIR spectral investigations of prepared undoped and WO3-or MoO3-doped glasses from ZnO-CdO-P2O5 glassy system were carried out before and after irradiation with a dose of 8 Mrad (= 8 x 10(4) Gy). The optical spectrum of the undoped glass reveals strong UV absorption band due to trace ferric ions present as trace impurity within the chemicals. The WO3 or MoO3-doped glasses show additional UV-visible bands due to the dominance presence of the low valence states of the two transition metal (TM) ions (M3+, M4+, M5+). Gamma irradiation extends and increases the UV absorption due to suggested photochemical reactions of ferrous iron present as impurity to react with positive holes during the irradiation process to transfer to additional ferric ions possessing their absorption in the UV region. The TM-doped glasses show some shielding behavior in almost the persistence of the visible spectra due to the TM ions. FTIR spectral bands are related to phosphate groups (mainly Q(2) and Q(3) units) in accordance with the high content of P2O5 (70 mol%). The effects of dopant ions on the IR spectra are limited due to the low percent (0.25 to 0.75 g/100 g) and their presence in modifying positions. Gamma irradiation decreases the intensity of some IR bands due to OH, water vibrations present mainly in terminal sites.