Oxygen-vacancy-mediated Negative Differential Resistance in La and Mg co-substituted BiFeO3 Thin Film

TL;DR

This paper investigates the negative differential resistance in La and Mg co-substituted BiFeO3 thin films, attributing it to oxygen vacancies and their dynamic behavior under electric fields at elevated temperatures.

Contribution

It reveals the origin of NDR in BLFM thin films as related to oxygen vacancies and their interaction with electric fields, providing new insights into defect-mediated electronic properties.

Findings

NDR observed above 80°C in BLFM thin films.

Oxygen vacancies are key to the NDR behavior.

Surface potential analysis supports defect-related mechanism.

Abstract

The conductive characteristics of Bi0.9La0.1Fe0.96Mg0.04O3(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 oC. The origin of the NDR behavior is shown to be related to the ionic defect of oxygen vacancies (VO..) 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 VO...