Leakage Current Properties of Cation-Substituted BiFeO₃ Ceramics

Abstract

Cation-doped BiFeO 3 ceramics were fabricated by sintering coprecipitated and calcined powders at 700–900 °C to study the effect of cation doping on the leakage current properties of the sintered samples. Among the dopants examined in this study, Ti 4+ , Sn 4+ , or Zr 4+ doping was found to effectively reduce the leakage current of the samples. In particular, a marked decrease in the leakage current density was achieved at 10% Ti 4+ doping, which also resulted in the structure change from rhombohedral to cubic. The codoping of Ti 4+ /Zn 2+ ions or Ti 4+ /Ni 2+ ions brought about a substantial reduction in the leakage current density of the bulk samples by about four or five orders of magnitude at a small doping amount of 2%. This can be explained by the combined effect of Ti 4+ doping, which basically contributes to the decreased number of oxygen vacancies in the sample, and Zn 2+ or Ni 2+ doping, which might assist the homogeneous substitution of Ti 4+ ions for the Fe 3+ sites.