Resistive Switching Effect of BiFeO ₃ Thin Film Under the Voltage Below the Coercive Voltage

To study the resistive effect of the Au/BiFeO ₃/SrRuO ₃ fabricated by the pulsed laser deposition on the SrTiO ₃ substrate, the resistive effect was characterized by the I-V curves. Due to the different work function between BiFeO ₃ and Au, BiFeO ₃ and SrRuO ₃, the stable Shottky contact was formed between the contact surface of Au/BiFeO ₃ and BiFeO ₃/SrRuO ₃. The Shottky barrier height was changed by application of external voltage to control the filling status of trap levels. Results show that from the I-V curve the film displays the resistive switching behavior under the voltage below the coercive voltage, with the resistance ratio as large as three orders. Through the fitting of I-V curves by different conduction mechanisms, it is confirmed that the conduction of the film is dominated by the space charge limited current (SCLC). The trapping effect was proposed as the resistive switching mechanism for the BiFeO ₃ thin film below the coercive voltage.