Electrical conductivity of ZrF 4AlF 3BaF 2Alkali Fluoride glasses

Abstract

The dc electrical conductivities, the activation energies for conduction and the high frequency dielectric constants were measured on glasses of compositions (100− χ)(0.6ZrF 4·0.1AlF 3·0.3BaF 2)· χRF, where χ ranges from 0 to 55, 35 and 25, respectively, for R = Li, Na and K. The elastic moduli of some of the glasses were also measured. A minimum of electrical conductivity and a maximum of activation energy for conduction were found around 20 mol% in the alkali fluoride (RF) concentration, when these preperties were plotted against the RF concentration. The occurrence of the minimum and the maximum was attributed to the change of the conducting species. That is, it was assumed that the conduction of these glasses is governed by the motion of fluoride ions in the low RF concentration region and by the migration of alkali ions in the high RF concentration region. The electrical conductivities of glasses with the same RF concentration were changed in the order of Li glass < Na glass < K glass in the low RF concentration region, whereas in the high RF concentration region, the order of the conductivity was different.