Nonvolatile Resistive Switching and Physical Mechanism in LaCrO_3 Thin Films

Polycrystalline LaCrO_3 (LCO) thin films are deposited on Pt/Ti/SiO_2/Si substrates by pulsed laser deposition and used as the switching material to construct resistive random access memory devices. The unipolar resistive switching (RS) behavior in the Au/LCO/Pt devices exhibits a high resistance ratio of \sim 10^4 between the high resistance state (HRS) and low resistance state (LRS) and exhibits excellent endurance/retention characteristics. The conduction mechanism of the HRS in the high voltage range is dominated by the Schottky emission, while the Ohmic conduction dictates the LRS and the low voltage range of HRS. The RS behavior in the Au/LCO/Pt devices can be understood by the formation and rupture of conducting filaments consisting of oxygen vacancies, which is validated by the temperature dependence of resistance and x-ray photoelectron spectroscopy results. Further analysis shows that the reset current I_\rm R and reset power P_\rm R in the reset processes exhibit a scaling law with the resistance in LRS (R_0), which indicates that the Joule heating effect plays an essential role in the RS behavior of the Au/LCO/Pt devices.