UV–visible and infrared spectroscopy of gamma-irradiated lithium diborate glasses containing SeO2

UV–visible spectroscopic studies of a base lithium diborate glass together with samples containing SeO2 substituting B2O3 have been measured before and after successive gamma irradiation. The optical absorption spectra of the base and SeO2-containing samples show charge transfer UV absorption bands which are related to the unavoidable contamination with trace iron impurities [mainly Fe3+ ions] within the raw materials used for the preparation of such glasses. The progressive introduction of SeO2 causes some changes in the intensity of the two UV bands which are identified at 235 and 285 nm instead of the three peaks already observed in the base glass at 235, 275, 310 nm. irradiation produces induced bands which are assumed to be generated from the intrinsic defects in the lithium diborate base glass together with the sharing of trace iron impurities through suggested photochemical reactions. The UV induced bands are observed to be highly intensified showing continuous growth with progressive irradiation and are identified at about 230, 285 and 310 nm together with a further induced broad visible band centered at about 550 nm. ed absorption measurements of the base lithium diborate glass reveal characteristic bands due to stretching and bending vibrations of both BO3 and BO4 units together with the far-infrared bands due to the modifier Li+ ions. The introduction of SeO2 causes some changes in the IR spectra due either to the sharing of SeO3 units and/or the polymerization of the borate network.