Enhanced Performance and In Situ TEM Investigation in High Entropy Alloy Electrode Based Memristors

Abstract

Recent developments in resistive switching random access memory (RRAM) have gained significant attention owing to their high-density storage, low power consumption, and fast switching. RRAM performance strongly depends on its electrode materials. Thus, high-entropy alloys (HEAs) provide notable advantages owing to their multifunctional properties. This study investigates the resistive switching behavior of an HEA (Cr, Mn, Fe, Co, Ni) top electrode with a ZnO dielectric layer. The device exhibited a large memory window (≈107), low SET voltage (1.5 V), fast switching (30 ns), superior endurance exceeding 106 pulse cycles, and long retention time (104 s). In situ transmission electron microscopy (TEM) provided direct observation of filament formation during voltage application. Energy dispersive X-ray spectroscopy (EDS), atom probe tomography (APT), and electron energy loss spectroscopy (EELS) analyses revealed HEA element diffusion and its role in stabilising the oxygen storage layer during switching cycles. These findings demonstrate the potential of the HEA/ZnO RRAM for next-generation memory applications with low power consumption and exceptional stability.