It was found that polarizability and charge non-uniformity in the cationic sub-lattice of the tysonite fluoride had essentially no effect upon the migration of F ions in the low-temperature region. On the other hand, they increased the mobility in comparison with isostructural trifluorides or rare-earth elements at high temperatures. The dynamic non-uniformity of the anionic sub-lattice was also decreased. The diffusivity at 473K was equal to 2.26 x 10-13m2/s, and the activation energy was 0.38eV.

M.G.Izosimova, A.I.Livshits, V.M.Buznik, J.V.Amelin, I.V.Murin, A.N.Murin: Izvestiya Akademii Nauk SSSR - Neorganicheskie Materialy, 1987, 23[12], 2056-60 (Inorganic Materials, 1987, 23[12], 1801-5)