Temperature and Composition Dependence of the Elastic Properties of Semiconducting (100 -x)V2O5-xPbO Oxide Glasses

Abstract

Semiconducting vanadate lead glasses with different PbO contents have been prepared by rapid quenching technique. Ultrasonic velocities and attenuation measurements have been performed over a wide range of temperatures from 150–480 K. Elastic moduli, Debye temperature and Poisson's ratio have been obtained for different PbO contents as a function of temperature. For a fixed temperature, the composition dependence of velocities and attenuation shows a monotonic variation with the addition of PbO. Nevertheless, the elastic moduli, Debye temperature, and Poisson's ratio exhibit anomalies at 33 wt% of PbO. The observed anomalies are discussed in terms of PbO acting as a network modifier or network former depending on the PbO content. In contrast to many other glasses a linear decrease in ultrasonic velocities and elastic moduli as a function of temperature is noticed without any indication of anomalies. These dependencies will be explained in terms of the structural softening taking place in the glasses. The measured acoustic loss and attenuation as a function of temperature show anomalies between 200 and 270 K depending on the PbO content. The anomalies in attenuation have been explained in terms of a thermally activated relaxation process.