Mechanical response of some peculiar superionic glasses at ultrasonic frequencies

Abstract

The mechanical relaxation processes in superionic iodomolybdate glasses have been revealed by ultrasonic measurements. The attenuation peaks of longitudinal and shear waves in (AgI)_1−x(Ag₂MoO₄)_x, with 0.25 ⩽ x ⩽ 0.4, at temperatures between 100 and 300 K have been analysed in terms of the Gaussian-type energy distribution. The analysis of the thermally activated relaxation processes of mobile silver ions has been done in terms of two different and overlapping anelastic relaxations. The different values of relaxation times and of activation energies obtained from the best fit of the internal friction may be due to the different local arrangement of the silver ions.