Linking hopping conductivity to giant dielectric permittivity in oxides

Abstract

With the promise of electronics breakthrough, giant dielectric permittivity materials are under deep investigations. In most of the oxides where such behavior was observed, charged defects at interfaces are quoted for such giant behavior to occur but the underlying conduction and localization mechanisms are not well known. Comparing macroscopic dielectric relaxation to microscopic dynamics of charged defects resulting from electron paramagnetic resonance investigations we identify the actual charged defects in the case of BaTiO3 ceramics and composites. This link between the thermal activation at these two complementary scales may be extended to the numerous oxides were giant dielectric behavior was found.