Resistive Switching in Semimetallic SrIrO3 Thin Films

Local electrical properties, measured by conductive atomic force microscopy, of semimetallic SrIrO3 thin films are reported. The appearance of an Anderson-type metal-insulator transition (MIT) triggered by disorder and spatial localization due to film thickness reduction is analyzed as well as their influence on the resistive switching behavior. For thin enough films (below similar to 3 nm) samples are insulating with hysteretic I-V curves indicative of reversible resistive switching behavior between two states of clearly different resistance at room temperature. A sharp transition into a low resistance state (LRS), i.e., an abrupt increase of the current intensity, is detected above a well-defined threshold voltage indicative of localization of charge carriers. On the other hand, thicker samples exhibit a semimetallic character, and I-V curves show progressive changes of the local resistance without a clearly defined threshold voltage, thus evidencing the absence of a MIT transition with a well-defined resistance jump between the different resistance states.