Electric breakdown of barium titanate: A model

A model is proposed to explain observations on electric breakdown of BaTiO₃ ceramics: Ceramics made by usual sintering technique contains TiO₂-rich intermediate layers between the grains of the polycrystalline structure. Field inhomogeneities are shown to result, with the field enhanced by factors of up to 100 or more in places. The very high field strength ensueing when the applied test voltage approaches its breakdown value causes inner field emission, with currents abruptly rising to very high values and thermally destroying the sample at once.