Dynamical response of borate glasses down to low temperatures

Relaxation dynamics of silver ions in the (AgI)x.(Ag2O.2B2O3)1−x superionic glasses have been studied as a function of temperature between 300 and 90 K in the frequency range from 10−3 to 109 Hz. The frequency dependent dielectric permittivity has been analysed in terms of conductivity as well as in the formalism of the electric modulus. From the conductivity spectra the Arrhenius dependence of d.c. conductivity as well as the power law exponent characterising the dispersive behaviour at high frequencies have been studied for samples with different AgI content. The analysis of the same data, at fixed frequencies and variable temperatures, in terms of the electrical modulus shows an impressive agreement between the dielectric and the mechanical relaxation process on the (AgI)0.6:(Ag2O.2B2O3)0.4 glass.