Resistive switching properties of electrode-SrZrO_3-SrRuO_3 heterostructures with different electrodes

摘要

We present investigations into the role of the top electrode on the reversible resistance-switching properties of SrZrO_3-based heterostructures. Cr-doped SrZrO_3, an insulating perovskite that is known to exhibit hysteretic resistance properties, was incorporated into a sandwich-like electrode-insulator-electrode structure using pulsed laser deposition. (100)-oriented SrRuO_3 was deposited as an epitaxial bottom electrode on (100)-oriented SrTiO_3 crystals. An epitaxial (100)-oriented 0.2% Cr-doped SrZrO_3 layer was deposited through a shadow mask to form the insulating layer of the heterostructure. Different top electrodes- polycrystalline and textured Pt, Au, and epitaxial SrRuO_3- were deposited through a shadow mask and were individually investigated with respect to the resistance values and switching behavior of the overall heterostructures (in a current perpendicular to the plane geometry). Switching was observed when Pt or Au was the top electrode but not when SrRuO_3 was the top electrode. Switching from resistance values of 24.2 kΩ to 3.4 kΩ was observed with Pt. Similar properties were observed for both polycrystalline and textured films. Switching from resistance values of 3.2 kΩ to 0.99 kΩ was observed with Au. The apparent difference in behavior is not consistent with the view that the resistance properties arise from a Schottky barrier derived from the work-function difference between the electrode and insulator.