The influence of Ag2O on the dielectric properties of LiF–CaO–B2O3 glasses

LiF-CaO-B2O3 glasses doped with different concentrations of Ag2O have been synthesized. The dielectric properties, viz., dielectric constant, loss tangent and AC conductivity were studied as a function of the concentration of Ag2O over a wide range of frequency and temperature. AC conductivity,s, is found to increase while the activation energy for AC conduction and is found to decrease with increase in the concentration of Ag2O. The AC conductivity of these glasses is found to obey the relation, sigma(w)=Aw(s); the low temperature part of the AC conductivity has been explained on the basis of quantum mechanical tunnelling of electrons. The density of the defect energy states N(E-F) near the Fermi level for these glasses has been evaluated and it is found to decrease with increase in the concentration of Ag2O. The range of the values of N(E-F) obtained suggests that the AC conductivity is due to the localized states is near the Fermi level. The conduction in the high temperature range could successfully be explained on the basis of ionic conduction.