Model of polarization conductivity in ionically conducting glasses

We have used a hopping conduction model to calculate the frequency-dependent polarization conductivity, [MATH] in ionically conducting glasses, and we have assumed that a short-range ionic hopping mechanism occurs based on a fluctuation process. We have underlined the fundamental differences between the frequency-dependent polarization conductivity due to "bound-charge" and the dc conductivity related to "free-charge" diffusion. The law [MATH] is observed as for electronic charge-carriers in amorphous substances. The expression of parameter s is modified by the introduction of a term connected with the fluctuation probability. A plot of the function T/1-s = f(T) shows a striking difference in behaviour (slopes) between ionic glasses (Na2O-3SiO2, (Ag2S)x (GeS21-x) and electronic amorphous solids