Phase diagram and high copper ion conductivity of the copper(I) chloride-rubidium chloride system

Abstract

The phase diagram of the CuCl—RbCl system has been determined by differential thermal analysis, X-ray diffraction analysis and electrical conductivity measurement. This system contains six intermediate compounds, Rb 2CuCl 3, RbCuCl 2, Rb 11Cu 14Cl 25, Rb 9Cu 16Cl 25, RbCu 2Cl 3 and Rb 3Cu 7Cl 10. Of these intermediate compounds, Rb 9Cu 16Cl 25 has a congruent melting-point at 169°C, and the other compounds have the incongruent melting-points. A single crystal of Rb 9Cu 16Cl 25 was prepared and the crystal form was determined to be cubic (space group I4 132) with a = 21.225 Å. Rb 3Cu 7Cl 10 has a high copper ion conductivity of 3.32 × 10 -3 S cm -1 at 25°C, while the other compounds are poor conductors.