Dielectric and Electrical Conductivity Relaxation in 0.5Li2O-0.5Na2O-2B2O3 Glasses

The frequency and temperature dependence of the dielectric constant, electric modulus, and electrical conductivity of the transparent glasses of composition 0.5Li2O-0.5Na2O-2B2O3 were investigated in the 100 Hz to 10 MHz frequency range. The dielectric data have been analyzed using the Cole–Cole equation with the addition of a conductivity term. The electrical conductivity was found to obey Jonscher’s universal law. Conductivity plots were not found to follow Summerfield scaling due to the mixed alkali effect. The imaginary part of electric modulus spectra was modeled using the Kohlrausch–Williams–Watts relation. The stretching exponent, β, was found to be 0.56 and temperature independent.