The conductivity of thin films was studied at frequencies of between 300Hz and 50kHz and at temperatures of between 300 and 500K. The conduction process was attributed to cation vacancy movement within the grains and through the grain boundaries. The former process could be described by an activation energy of 0.84eV and a pre-exponential factor of 10-14s. The parameters for the latter process were 1.12eV and 10-16s. A dielectric permittivity of 1000 at low frequencies was attributed to the cation vacancy space charge over forest dislocations at the electrode interface.

S.M.Babulanam: Physica Status Solidi A, 1985, 90[2], 755-62