Characterization of some lead vanadate glasses

Abstract

Studies on lead vanadate glasses modified with Li 2O have been carried out. Elastic properties and Debye temperature have been investigated using sound velocity measurements at 4 MHz. The ultrasonic and the IR spectroscopic studies have been employed to investigate the structure of lead vanadate glasses in the presence of Li 2O. IR analysis indicates that increasing the vanadate content causes a shift of the bands to higher wave number and to higher relative area which was attributed to the higher dissociation energy of V 2O 5 than that of PbO. Thus, the average force constant of VO 5 structural units increases with increasing V 2O 5 content. The change of density and molar volume with V 2O 5 content reveals that the decrease in density is related to the replacement of high dense PbO with low dense one V 2O 5, where the increase in the molar volume can be attributed to the larger packing factor of V 2O 5 than that of PbO. The observed compositional dependence of the elastic moduli is interpreted in terms of the effect of V 2O 5 on the coordination number of the vanadate and lead structural units.