Comparative spectral and shielding studies of binary borate glasses with the heavy metal oxides SrO, CdO, BaO, PbO or Bi2O3 before and after gamma irradiation

Abstract

This work aims to compare the experimental shielding behavior of some prepared binary borate glasses with SrO, CdO, BaO, PbO or Bi2O3 towards successive gamma irradiation by investigating their combined optical and FTIR spectral measurements before and after gamma irradiation. Optical spectra of all the samples reveal strong UV absorption which is related to the presence of unavoidable trace iron impurities (Fe3+ ions) contaminated within the raw materials which were used for the preparation of the studied glasses. Additional near visible bands are observed in the two lead borate and bismuth borate glasses due to characteristic absorption of Pb2+ and Bi3+ ions. Gamma irradiation causes varying responses depending on the type of glass. Bismuth borate glass shows highly marked shielding towards successive gamma irradiation while lead borate glass reveals resistance in low dose (4Mrad) and produces induced defects at high dose (8Mrad). The other glasses show obvious generation of induced defects upon gamma irradiation. FTIR spectra of the glasses reveal vibrational modes characteristic to combined presence of triangular and tetrahedral borate units in their specific different wavenumbers besides the presence of interfering structural PbO and BiO linkages in the lead borate and bismuth borate glasses. Gamma irradiation produces limited changes in the FTIR spectra specifically the intensity of some vibrational modes while the bismuth borate glass has proved to be the best radiation-shielding candidate when comparing the combined spectral results after successive gamma irradiation.