Ultrasonic Relaxation Of Tewb Glasses At Low Temperatures

The ultrasonic relaxation of tellurite glasses xB(2)O(3) - 70 TeO2 - (30 - x) WO3, 0 <= x <= 30 mol% was investigated by measuring the ultrasonic attenuation (alpha(L)) in these glasses in the thermal range 140-300 K (T) at various frequencies (f). Some characteristics can be obtained from the relation of alpha(L)-T, such as the average activation energy (E-p) and the attempt frequency (f(0)). The variables Ep and f0 are a function of frequency and B2O3 content. Moreover, the relation alpha(L)-T accounts well for the oscillations of the oxygen atoms in a relaxation process. Such a physical process is originated from transmitting ultrasonic energy to the oscillating oxygen atoms in a dual-well potential. The relaxation process is inspected by a model named central force one. The subtracted different physical variables from such a model are a function of B2O3 content.