Suppressing Electrode Diffusion via Interfacial Engineering for High-Temperature Memristors

• • Graphene bottom electrode suppresses W diffusion at 800 °C, enabling stable memristive switching, whereas Pt/HfOx/W devices fail due to W migration and WOx formation, locking in ON state. • • Gra/HfOx/W memristor achieves data retention at 700 °C for 50 h, endurance of 10^9 cycles, ON/OFF ratio >10^3, and operation voltage ~1.5 V, outperforming conventional high-temperature electronics. • • Pt/HfOx/W devices annealed at 800 °C for 10^4 s exhibit rapid switching to ON state and remain there, attributed to W atoms diffusing across HfOx to Pt electrode, as confirmed by EDS and STEM-EELS. • • HRTEM-EDS imaging reveals mushroom-like WOx features at the W/HfOx interface in Pt-based devices, while Gra-based devices show no such features, indicating graphene's effectiveness as a diffusion barrier.