Ultrasonic investigations of CuO-P2O5 glass

The ultrasonic velocity and attenuation in four different samples of the (CuO)(x)-(P2O5)(1-x) glass system (x = 0.1500, 0.3030, 0.3768, 0.5106) have been measured at temperatures between 80 and 300 K using the ultrasonic pulse echo overlap technique at 10 MHz. The samples were prepared by the melt-quench method. The velocity data have been used to find the elastic moduli and Debye temperature for each composition. The results indicate that, for each composition, the velocities decrease slowly and steadily with increasing temperature and there is no indication of a minimum in the variation of velocity with temperature unlike many other glasses. The dependence of ultrasonic velocity and attenuation with temperature has been interpreted in terms of a thermally activated relaxation process. The model is based on an asymmetric double-well potential having distribution of both the barrier height and the asymmetry between the two wells. Attempts have been made to explain the apparent discrepancy found in the velocity variation between the theory and experiment.