Spectroscopic Proof of the Correlation between Redox-State and Charge-Carrier Transport at the Interface of Resistively Switching Ti/PCMO Devices

By using hard X-ray photoelectron spectroscopy experimentally, proof is provided that resistive switching in Ti/Pr0.48Ca0.52MnO3 (PCMO) devices is based on a redox-process that mainly occurs on the Ti-side. The different resistance states are determined by the amount of fully oxidized Ti-ions in the stack, implying a reversible redox-reaction at the interface, which governs the formation and shortening of an insulating tunnel barrier.