Structural and conductivity studies were made of monocrystals of the -phase of dry-synthesized Pb0.9K0.1F1.9. The material was cubic (a = 0.5941nm, Fm3m) and had a conductivity, T, of 1.4SK/cm at 300K. The associated activation energy was 0.24eV. It was noted that the crystal structure was similar to that of -PbF2; with K ions in cation sites. Because the F vacancies appeared in their normal tetrahedral positions, the F ions could move easily between tetrahedra via the F vacancies. It was concluded that anharmonic thermal vibrations of the F ion did not play a significant role in ionic conduction, and that the high ionic conductivity could be attributed to the usual F vacancies.

Y.Ito, T.Mukoyama, F.Kanamaru, S.Yoshikado: Solid State Ionics, 1994, 73[3-4], 283-7