Memory resistive switching in CeO₂-based film microstructures patterned by a focused ion beam

Heteroepitaxial CeO₂ (80 nm)/La_0.5Sr_0.5CoO₃ (500 nm) film structure has been pulsed laser deposited on a sapphire substrate. The Ag/CeO₂ microjunctions patterned by a focused ion beam on a La_0.5Sr_0.5CoO₃ film exhibit reproducible reversible switching between a high resistance state (OFF) with insulating properties and a semiconducting or metallic low resistance state (ON) with resistance ratios up to 10⁴. The influence of micro-scaling and defects formed at the cell boundaries during etching on its electrical characteristics has been analyzed. The appearance of a switching channel at the moment of the electrical forming, responsible for the memory effect, has been proved, along with a mechanism of a self-healing electrical breakdown. - Highlights: • Ag/CeO₂/La_0.5Sr_0.5CoO₃ microstructures were patterned by a focused ion beam. • Reproducible memory resistive switching was discovered in Ag/CeO₂ microjunctions. • Micro-scaling affects electrical characteristics of Ag/CeO₂ microjunctions. • A mechanism of a self-healing breakdown was discovered