Interfacial resistive oxide switch induced by reversible modification of defect structures

We report on electric field induced bipolar resistive switching in metal electrode-Pr0.7Ca0.3MnO3 interfaces that exhibit hopping transport. The electrical transport data show that the number of hopping steps needed for a carrier to cross the interfacial layers changes while switching between high and low resistance states. Furthermore, the frequency response of the interfacial ac impedance shows that the layers can be modeled as a percolation network with an effective resistance that is dominated by its bottleneck section. We therefore propose that a reversible creation/annihilation of a few hopping sites within this bottleneck serves as the switching mechanism, which may be of use in the design of future nonvolatile memory devices