Giant dielectric behavior in CaLaAlO4 ceramics

摘要

CaLaAlO4 ceramic samples were prepared by solid state reaction. The low-frequency (20-10.7 Hz) dielectric properties were investigated in the range from room temperature to 700 degrees C. It was found that the CaLaAlO4 ceramic samples show giant dielectric behavior above 100 degrees C. The behavior is composed of two thermally activated dielectric relaxations. The low-temperature relaxation is caused by the bulk response related to the hopping motion of oxygen vacancies, and the high-temperature one is an interfacial relaxation due to grain boundaries. Our results revealed that the giant dielectric behavior is mainly caused by the interfacial relaxation. (C) 2016 Elsevier B.V. All rights reserved.