Switching Mechanism of Resistive Random Access Memory Using High-Temperature Cuprate Superconductor Bulk Single Crystal

Abstract

We made resistive random access memory (ReRAM) structures of Al/Bi₂Sr₂CaCu₂O_8+δ (Bi-2212) single crystal/Pt and Pt/Bi-2212 single crystal/Pt, and evaluated both their memory characteristics and superconducting properties. The memory effect was confirmed only in the former. Taking advantage of the large anisotropy of a Bi-2212 single crystal, it was clarified that the memory effect occurred at the boundary between Al and Bi-2212. The memory effect was enhanced with decreasing critical temperature by annealing the sample. This showed that the introduction of oxygen vacancies to the Bi-2212 single crystal was required for the development of the memory effect and could be achieved by depositing electrodes with low Gibbs free energies. The model which explains the resistance switching of perovskite-oxide-based-ReRAM was proposed based on the results.