Tri-state bipolar resistive switching behavior in a hydrothermally prepared epitaxial BiFeO3 film

• BFO films are epitaxially grown on NSTO (001) substrate by hydrothermal method.
• The Pt/BFO/NSTO devices exhibit multilevel bipolar resistive switching behavior.
• The Pt/BFO/NSTO devices possess excellent retention and endurance characteristics.

A crystalline BiFeO3 (BFO) heteroepitaxial film was produced by mild hydrothermal epitaxy on a Nb–SrTiO3(100) (NSTO) substrate. The resulting coated substrate was used to fabricate a Pt/BFO/NSTO heterostructure device. The device exhibits reversible bipolar resistive switching behavior. The resistance states can be reversibly switched among multiple levels, by changing the magnitude of the reset pulse voltage. This illustrates the devices potential in multilevel nonvolatile memory devices. The resistive switching behavior of the device is attributed to trap-controlled space-charge-limited current conduction, which is controlled by oxygen vacancies in the film. The modulation of the Pt/BFO Schottky-like junction depletion under an applied electric field is thought to be responsible for the resistance switching behavior of the device, in the carrier injection-trapped/detrapped process.

An epitaxial BiFeO3 (BFO) film, with crack-free and compact surface, is hydrothermally grown on a single-crystal Nb-doped SrTiO3 (NSTO) (001) substrate. The stable tri-state bipolar switching behavior of a ReRAM device containing the Pt/BFO/NSTO structure is achieved by changing the reset voltage (−2 V and −3 V) at room temperature.Figure optionsDownload as PowerPoint slide