Interfacial resistive switching properties in Ti/La 0.7Ca 0.3MnO 3/Pt sandwich structures

Abstract

La 0.7Ca 0.3MnO 3 (LCMO) films with and without in situ oxygen annealing have been prepared by pulsed laser deposition. After depositing Ti top electrodes (TEs) at room temperature, both the Ti/LCMO/Pt structures show a reversible, nonlinear, and hysteretic current-voltage (I-V) characteristics. The switching ratio between high and low resistance state is significantly reduced by in situ oxygen annealing due to the decrease of oxygen vacancies in the surface of LCMO film. Moreover, the switching ratio is also significantly reduced by depositing Ti TEs at a higher temperature such as 200 °C. These results suggest that the oxidation/reduction reaction between the TiO x interlayer and the oxygen-deficient LCMO layer plays a crucial role in the resistive switching of the Ti/LCMO/Pt structures. Furthermore, it is also suggested that the formation/rupture of the conductive filament paths in the TiO x interlayer by the electrochemical migration of oxygen is responsible for the anomalous changes of current and the large hysteresis in the I-V curves.