The F-ion conductivity of the non-stoichiometric tysonite phases, La0.95(Ba1-xSrx)0.05F2.95, where x ranged from 0 to 1, was investigated by means of impedance spectroscopy. Electrophysical measurements were performed at frequencies ranging from 5Hz to 0.5MHz, and at temperatures of 300 to 700K. A discontinuity was observed, in the temperature dependence of the conductivity, at 410 to 430K. The behavior of the temperature dependence of the conductivity was explained in terms of a transport model which took account of the migration of F ions between various non-equivalent structural sites. The maximum value of the conductivity at 293K was equal to 2 x 10-4S/cm for La0.95Sr0.05F2.95.

N.I.Sorokin, M.V.Fominykh, E.A.Krivandina, Z.I.Zhmurova, B.P.Sobolev, ·O.I.Lyamina: Fizika Tverdogo Tela, 1998, 40[4], 658-61 (Physics of the Solid State, 1998, 40[4], 604-7)