Ultrasonic velocity and absorption in (V2O5)(x)(GeO2)(y)(P2O5)(1-x-y) glasses

The velocity and attenuation of longitudinal and transverse ultrasonic waves in four different compositions of (V2O5)(x)(GeO2)(y)(P2O5)(1-x-y) glass system with P2O5 concentration ranging from 2.55 to 15.44 mol% have been measured at temperatures between 80 and 300 K using the ultrasonic pulse echo technique at 8 MHz. The results indicate that for low concentration of GeO2 (y < 0.5) the velocities decrease slowly and monotonically throughout the entire range of temperature but for higher concentration (y > 0.5) velocity variation shows a minimum. The attenuation shows broad high temperature relaxation peak for all samples.