Inhomogeneous conductor model for relaxation behaviour in oxide glasses

An inhomogeneous conductor model comprising diagonal layers of phases having drastically different conductivities has been described for calculating the dielectric modulus values as a function of frequency of alkali-containing oxide glasses. The local conductivity is assumed to have a sinusoidal variation with the spatial co-ordinate. The theoretically calculated values are found to be in excellent agreement with the experimental data. The latter have been analysed by Kohlrausch-Williams-Watts (KWW) stretched exponential function. The exponent β is shown to be dependent on the conductivity fluctuation in the conducting phase of the inhomogenous conductor model.