FLUORIDE ION CONDUCTORS RPbF_3 (R=Rb, Cs) STUDIED BY X-RAY DIFFRACTION AND NMR

摘要

The crystal structure and ion conduction mechanism of the title compounds were investigated by means of DTA, X-ray diffraction, and NMR. The cubic phase of the Rb salt showed a high conductivity above ca. 500 K. This is responsible for the diffusion of the fluoride ions through octahedral and tetrahedral interstitial sites. The low temperature phase of the Cs salt showed a fairly high conductivity at room temperature. This is responsible partly for point defects in octahedral interstitial sites.