Clustering and anionic mobility inside the Sr 1− xBi xF 2+ x solid solution

Abstract

The conductivity parameters, number of charge carriers and frequency of hopping, have been determined from an analysis of a.c.-conductivity data of the fluorite-type Sr 1− x Bi x F 2+ x (0 ≤ x ⪅ 0.50) solid solution. The composition dependence of the fraction of charge carriers per unit cell is in agreement with the estimations made on the basis of the clustering process model which assumes that the interstitial fluoride ions of F′ type are the charge carriers at long range in Sr 1− x Bi x F 2+ x .