Dependence of the conductivity on the concentration and the hopping frequency of charge carriers in fluoride glasses

Abstract

The conductivity spectra of fluoride glasses in the system ZrF₄-BaF₂-YF₂-LiF with varying LiF content has been reported at different temperatures in the frequency range 10 Hz-2 MHz. The experimental data have been analyzed in the framework of the Almond-West formalism. The concentration and hopping frequency of the charge carriers, the dc conductivity, and the activation energy have been determined from the analysis of the data. The concentration of the charge carriers is observed to be almost independent of temperature and weakly dependent on composition. Both the hopping frequency and the dc conductivity exhibit a minimum at LiF content x_LiF=0.20. It is observed that the charge transport in these glasses occurs by the hopping mechanism and the strong electrolyte model is applicable.