Ac conductivity and dielectric relaxation in ionically conducting soda-lime-silicate glasses

The frequency dependent conductivity and dielectric relaxation of alkali ions in some soda-lime-silicate (Na2O-CaO-SiO2) glasses are investigated over a frequency range from 50 Hz to 1MHz and in a temperature range from room temperature to 603 K by using alternating current impedance spectroscopy. The conductivity isotherms show a transition from frequency independent dc region to dispersive region where the conductivity continuously increases with increasing frequency. The electric modulus representation has been used to provide comparative analysis of the ion transport properties in these glasses. The scaling behavior of imaginary part of electric modulus indicates that all dynamical processes occurring at different frequencies give the same activation energy. (C) 2008 Elsevier B.V. All rights reserved.