Oxygen-vacancy-mediated negative differential resistance in la and Mg co-substituted BiFeO ₃ thin film

The conductive characteristics of Bi _0.9La _0.1Fe _0.96Mg _0.04O ₃ (BLFM) thin film are investigated at various temperatures and a negative differential resistance (NDR) is observed in the thin film, where a leakage current peak occurs upon application of a downward electric field above 80 °C. The origin of the NDR behavior is shown to be related to the ionic defect of oxygen vacancies (V _O ^••) present in the film. On the basis of analyzing the leakage mechanism and surface potential behavior, the NDR behavior can be understood by considering the competition between the polarized distribution and neutralization of V _O ^••.