Electrical and thermodynamic properties of Cs0.97 Rb0.03H2PO4

Abstract

The transport properties of Cs0.97Rb0.03H2PO4 have been studied using polycrystalline samples and single crystals. The mixed salt is isostructural with cesium dihydrogen phosphate and has slightly smaller unitcell parameters. The cation substitution increases the low-temperature ionic conductivity of the material by about two orders of magnitude but has an insignificant effect on the conductivity of the high-temperature phase. The low-temperature conductivity of single-crystal samples exhibits significant anisotropy, with σ a < σ b±c . The conductivity of the polycrystalline material is close to σ b±c . The substitution reduces the temperature of the superionic phase transition by 20°C and enhances the thermal stability of the high-temperature phase at low humidity (1 mol % H2O).