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.