Enhancement of p-type conductivity in nanocrystalline BaTiO3 ceramics

Abstract

Undoped BaTiO3 ceramic samples with an average grain size of ∼35nm were prepared and the electrical properties investigated. The defect structure is dominated by acceptor impurities; therefore, the conductivity of nanocrystalline BaTiO3 is of p-type. Comparing with microcrystalline BaTiO3, the conductivity of nanocrystalline BaTiO3 is about 1 to 2 orders of magnitude higher and the activation energy remarkably lower, which is ascribed to a greatly reduced oxidation enthalpy in nanocrystalline BaTiO3 (∼0.3 versus ∼0.92eV for microcrystalline BaTiO3).