Single crystals of the solid solution, Pb1−xSnxF2 (x = 0, 0.1, 0.2), were used to investigate the correlation between structure and ionic conduction, via crystal structure analysis and studies of the frequency dependence of the complex conductivity, using impedance spectroscopy. The frequency dependence was measured over wide frequency and temperature ranges, and the hopping frequency of fluoride ions was estimated. It was confirmed that the activation energy for mobile fluoride-ion generation was very small in Pb0.9Sn0.1F2 and Pb0.8Sn0.2F2, and that all of the fluoride ions were mobile. It was suggested that the activation energy, for fluoride-ion hopping to adjacent sites, was determined by bottlenecks made up of (Pb2+, Sn2+) ions.

Fluoride Ion Conduction in Pb1−xSnxF2 Solid Solution System. S.Yoshikado, Y.Ito, J.M.Réau: Solid State Ionics, 2002, 154-155, 503-9