Conduction in perovskite-type halides was measured at temperatures of between 150C and the melting point. The ionic transport number was determined by using the Tubandt, emf and ion-blocking methods. The ionic conductivity was close to that of halide-ion conductors such as PbBr2. The ionic transport number was found to be greater than 0.9. The conduction was attributed to the migration of Br-ion vacancies. The activation energy for the migration of Br was equal to 0.25eV. The vacancy diffusion coefficient was found to be very large. However, impurity doping did not markedly increase the ionic conductivity; due to low dopant solubility.

J.Mizusaki, K.Arai, K.Fueki: Solid State Ionics, 1983, 11[3], 203-11