Electrical conductivity and dielectric behaviour of lithium diborate glasses containing Gd3+ ions

The electrical conductivity and dielectric characteristics of gadolinium doped lithium diborate samples were analysed by the impedance spectroscopic method in temperature and frequency range of 393 K-573 K and 100 Hz-5 MHz respectively. Obtained dc activation energy values with Arrhenius plots vary non-linearly with Gd3+ ions. Increase in dielectric loss and dielectric permittivity were observed with temperature variation and results were analysed on the basis of frequency dependent electron hopping in addition to the electron polarization. Modified KWW model was fitted on account of asymmetric nature in the frequency response of shape parameters. The imaginary part of complex electric modulus obtained from the fit were found to be consistent with glass composition. The conductivity modulus was reasonably fitted with stretched exponential relaxation functions and the stretched exponential values were found to be independent of temperature.