Write-once-read-many-times memory device based on Pt/BiFeO3/LaNiO3 heterostructures

Nonvolatile memory devices based on resistive switching effects are promising candidates for next generation high performance nonvolatile data storage. Here, we report the write-once-read-many-times (WORM) resistive switching behavior for the first time in Pt/BiFeO3/LaNiO3 heterostructures. BiFeO3 thin films with (1 0 0) preferred orientation have been prepared by RF magnetron sputtering combined with annealing at temperature higher than 600 ℃, and show excellent WORM resistive switching behaviors with data retention for>3600 s and reliable endurance for>1000 cycles. The devices with BiFeO3 annealed at 650 ℃ exhibit extremely high ON/OFF ratio (>3 × 104) and low switching voltage (∼3 V) due to the high quality of BiFeO3 thin films. The observed resistive switching behavior is attributed to the formation of permanent conducting filaments that composed of oxygen vacancies. These results demonstrate that BiFeO3 is promising for novel WORM memory device applications.