Dielectric properties of ErFeO3 ceramics over a broad temperature range

Erbium orthoferrite (ErFeO3) ceramics were prepared by the solid state reaction. The dielectric properties of the samples were investigated over a broad temperature (120-850 K) in the frequency range ranging from 50 Hz to 10 MHz. The sample shows three dielectric responses without colossal dielectric constant behavior. The first dielectric response occurring around 200 K 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 550 K 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 725 K also exhibits as a relaxor-like behavior. It was found to be an artificial effect caused by negative capacitance. (C) 2014 Elsevier B.V. All rights reserved.