Interface-Induced Synaptic Performance in CeO₂/La_0.8Ba_0.2MnO₃ Oxygen Reservoir Junction

Realizing next-generation intelligent applications requires novel resistive switching devices that can operate with low power, high stability, and desired neuromorphic performance. La_0.8Ba_0.2MnO₃ (LBMO), a functional complex oxide exhibiting a room-temperature metal-insulator transition, shows promise in this context. In this work, we demonstrate interface-engineered resistive switching in the LBMO thin film junction by introducing an ultrathin CeO₂ insertion layer. Compared to bare LBMO film, which requires higher forming voltages and suffers from limited stability and large cycle-to-cycle variability, the CeO₂/LBMO (LBC) device exhibits stable, low-power bipolar resistive switching. The LBC device achieves a low forming voltage of 2.2 V, an ON/OFF ratio of ∼10², endurance of 600 switching cycles, and data retention of 10³ seconds. The improved performance is attributed to controlled oxygen vacancy migration and redistribution facilitated by the CeO₂ interlayer. Furthermore, the LBC device displays, for the first time, bioinspired synaptic behaviors, such as gradual potentiation and depression under pulsed stimuli, and exhibits linear plasticity under nonidentical pulse schemes, effectively emulating synaptic weight modulation. Our results demonstrate an interface-induced resistive switching device as a compelling candidate for next-generation neuromorphic components.