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/Pr₀.₄₈ Ca₀.₅₂ MnO₃ (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.