Low programming voltage resistive switching in reactive metal/polycrystalline Pr0.7Ca0.3MnO3 devices

The resistive switching (RS) characteristics of Pt/Pr0.7Ca0.3MnO3 (PCMO)/W devices with a submicron via-hole structure are investigated. Reproducible and stable switching behavior was achieved in voltage sweeping cycles, while the resistance change was more than two orders of magnitude. No forming process was required to induce the RS. Detailed current density–voltage analysis suggest that the oxidation and reduction reaction of an interfacial WOx layer by electrochemical migration of oxygen between the W bottom electrode and the PCMO layer plays a crucial role in the RS of the Pt/PCMO/W structures Furthermore, the relatively low programming voltage (±1.5±1.5 V), which is significantly less than the values previously reported in chemically reactive metal/PCMO devices, might be ascribed to the thermal-assisted RS and the unique properties of W metal and its oxides in nano-scale devices.

Research highlights
► Pt/Pr0.7Ca0.3MnO3 (PCMO)/W devices with a 250 nm via-hole structure.
► Reproducible and stable resistive switching behavior.
► Low programming voltage (±1.5 V).
► Large OFF/ON ratio (>100).
► No forming process.
► The oxidation and reduction reaction of an interfacial WOx layer.
► Thermal-assisted RS in nano-scale devices.