The frequency and temperature dependence of ac electrical conductivity  dielectric constant  dielectric loss  and loss tangent  in the temperature range 280-360K and frequency range 40Hz-2MHz have been made for  system  0.00, 0.15, 0.20 and  The powder samples were used in the form of compressed pellets. The frequency dependence of  follows the universal law with the relation:  where Sis the frequency exponent. The parameter Swas found to decrease with increasing the temperature. A comparison between values of this exponent with those numerically calculated from different conduction models reveals that correlated barrier hopping (CBH) model is the proper model to describe the acconduction mechanism. The maximum barrier height  and the minimum hopping distance  were calculated. It was verified that both dielectric constant and loss increased with the increase in temperature and decreased with the increase in frequency.

acelectrical conductivity, maximum barrier height, minimum hopping distance, CBH model.