Comparative shielding behavior of binary PbO-B2O3 and Bi2O3-B2O3 glasses with high heavy metal oxide contents towards gamma irradiation revealed by collective optical, FTIR and ESR measurements

Selected glasses with high percent of heavy metal oxides (60-85 mol%) from the two binary systems (PbO-B2O3) and (Bi2O3-B2O3) were prepared. Collective characterization of the prepared glasses was carried out through optical, FTIR and ESR spectral measurements before and after gamma irradiation. Optical absorption data of these glasses indicate the appearance of distinct UV absorption bands which are related to unavoidable contaminated trace iron impurities (Fe3+ ions) together with the presence of absorption due to Pb2+ or Bi3+ ions. Gamma irradiation causes some obvious variations in the UV spectra of the lead borate glasses but the bismuth borate glasses are more stable. FTIR spectral measurements reveal the appearance of vibrational bands due to triangular BO3 and tetrahedral BO4 groups within their different characteristic wavenumbers. The deconvoluted IR spectra refer to the interfering vibrational bands due to PbO4, BiO3, BiO6 groups beside the presence of the two highly distinguish differently coordinated borate groups (BO3, BO4). The effects of gamma irradiation on the FTIR spectra are limited on lead borate glasses and bismuth borate glasses but are more noticed in the equalization of the intensities of both the vibrations due to tetrahedral and triangular borate groups due to the light weight of the boron element which shows response in triangular groups but less effect in compact tetrahedral borate groups. Also, the near-IR bands due to vibrations of OH, water are observed to decrease dut to their loose bonding in the network.ESR data indicate the stabilization upon irradiation of Bi2O3-B2O3 glass while the PbO-B2O3 show small changes.