Dielectric properties of ErFeO3 ceramics over a broad temperature range

Abstract

Erbium orthoferrite (ErFeO3) ceramics were prepared by the solid state reaction. The dielectric properties of the samples were investigated over a broad temperature (120–850K) in the frequency range ranging from 50Hz to 10MHz. The sample shows three dielectric responses without colossal dielectric constant behavior. The first dielectric response occurring around 200K is a thermally activated relaxation and argued to be a polaron relaxation caused by the hopping motions of charge carriers between Fe2+ and Fe3+. The second response occurring around 550K shows a relaxor-like behavior. It contains two relaxation processes: dipolar-type and Maxwell–Wagner-type relaxations induced by the hopping motions of oxygen vacancies. The third one occurring around 725K also exhibits as a relaxor-like behavior. It was found to be an artificial effect caused by negative capacitance.