UV-Visible and Infrared Spectra of Gamma-Irradiated Transition Metals-Doped Lead Borate Glasses

The UV-visible spectra of undoped and nominaliy transition metals (Ti -> Cu) doped lead borate glasses have been measured from 200 to 1000 nm before and after various doses of gamma-ray irradiation. In the undoped lead borate glass, strong charge transfer ultraviolet absorption bands are observed which are related mostly to trace iron impurities and the possible sharing of Pb2+ ions. In transition metal (TM) doped glasses, characteristic absorption bands are recorded due to each specific TM ion which may interfere with that due to iron impurities. Gamma (gamma-ray) irradiation reveals significant changes depending on the TM ion and some of the ions show retardation effect as observed in the induced bands. The responses of the undoped and TM-doped glasses to gamma-ray irradiation are related to the formation of induced colour centers associated with the intrinsic or extrinsic defects in the glasses. The rates of formation or growth behaviour of the various induced defects are believed to approach saturation with prolonged irradiation.