Relaxation of ultrasonic waves in ternary TeO2-V2O5-Sm2O3 glasses

Abstract

Studies were carried out on the attenuation of longitudinal ultrasonic waves in tellurite glasses containing vanadium and samarium oxides with different concentrations, using the pulse echo technique. Glass samples were prepared in the form (composition in mol%): 65 TeO2 - (35 - x) V2O5 - x Sm2O3, where x = 0.1, 0.5, 1.0, 2.0, 3.0, 4.0 and 5.0 mol%. The temperature dependence of the attenuation at ultrasonic frequencies of 2, 4, 6, and 10 MHz in the temperature range 150 to 280 Κ was proved. The shape of the loss peaks, i.e. the relaxation spectra, showed the presence of well-defined peaks at various temperatures depending upon glass composition and operating frequency. It was observed that these loss peaks shift to higher temperatures with increasing frequency suggesting some kind of relaxation process. Activation energies of the relaxation process, and deformation potential were calculated. Results showed that activation energies are strongly dependent on the samarium oxide content. Deformation potential is also frequency- and composition-dependent. Discussion of the results obtained in this study is reported.