Optical and μ-FTIR mapping: A new approach for structural evaluation of V2O5-lithium fluoroborate glasses

Collective optical and FTIR spectral measurements were carried out for undoped and V2O3 doped lithium fluoroborate glasses before and after gamma irradiation (8 Mrad). The undoped glass shows strong UV absorption which is related to the presence of unavoidable trace iron (Fe3+ ions) present as unavoidable impurities. The V2O5-containing glasses reveal additional UV-near visible bands due to the presence of vanadium ions mainly in the pentavalent state with some contribution of trivalent vanadium ions. The studied glasses show marked resistance to gamma irradiation, revealing the maintenance of the optical spectral curves without variations. FUR spectra reveal vibrational bands due to borate groups in triangular and tetrahedral coordination by the sharing of suggested (BO3F-) tetrahedral units through the modification effect of LiF on B2O3. The suggested tetrahedral units show similar vibrational modes in their wavenumbers to (BO4) units formed by alkali oxide. A new micro-FTIR mapping in combination with ordinary FTIR was also studied for further insight of the distribution of vibrational modes and structural arrangements within the studied glasses. 2015 Elsevier Ltd. All rights reserved.