ac conductivity of Li2ONa2OB2O3 mixed-alkali glasses: Analysis due to transition rate distribution

Abstract The complex ac conductivity of Li 2 ONa 2 OB 2 O 3 glasses was measured in the frequency range from 5Hz to 500 kHz and in the temperature range from 200 to 400°C. The observed results were analyzed by using the complex nonlinear least square fitting technique. In order to describe the frequency dependence of the conductivity, the distribution function for the transition rate of mobile ions, P (γ), was defined and was calculated by applying the inverse Stieltjes-Hilbertt transform to the experimental values. The form of P (γ) in the present mixed alkali glasses shows a broad enhanced peak in the region of low transition rate, which demonstrates the mixed-alkali effect on the ac conductivity.