Optical properties of vanadium-doped bismuth borate glasses before and after gamma-ray irradiation

UV-visible, infrared and Raman spectra, together with thermal properties, were measured for glasses from the system Bi2O3-B2O3-V2O5 before and after successive gamma irradiations. The UV-visible spectrum of the undoped glass before irradiation reveals five UV bands at 210, 275, 310, 350 nm, an intense band at 380 nm and a visible band at 420 nm due to the possible combined presence of trace iron impurities and Bi3+ ions. The V-doped glasses reveal six UV bands and two visible bands, probably arising from vanadium ions in three possible valencies, V3+, V4+ and V5+, beside that due to trace iron impurity beside Bi3+ ions. The spectra reveal an obvious resistance of the glasses to successive gamma irradiation. The Raman and infrared spectra show characteristic absorption bands, which indicate the sharing of Bi3+ ions as glass-forming (BiO6) octahedral units together with the presence of various groups of the borate network.