Shielding behavior of V2O5 doped lead borate glasses towards gamma irradiation

Undoped lead borate glass of the composition PbO 70%-B2O3 30% together with samples of the same composition and doped with varying V2O5 contents were prepared. UV-visible absorption spectra were measured out in the range 200-1500nm before and after successive gamma irradiation. Infrared absorption measurements within the range 4000-400cm(-1) were carried out for the undoped and V2O5 doped samples before gamma irradiation and after being irradiated with a dose of 6 Mrad. All the glass samples are observed to absorb strongly in the UV region due to the combined contributions of absorption due to trace iron impurities and that from the divalent lead Pb2+ ions. The V2O5-doped glasses reveal extra visible absorption bands which are attributed to the existence of V3+ ions in measurable content but not neglecting the other valence states of vanadium ions (V4+, V5+). Infrared absorption spectra indicate the presence of both triangular and tetrahedral borate groups besides the sharing of lead ions in network forming and network modifying sites. (C) 2011 Elsevier B.V. All rights reserved.