Resistive Switching in Individual Co/ZnO Core/Shell Nanoparticles Formed via Inert Gas Condensation and Selective Oxidation

Abstract

Magnetron sputtering inert gas condensation is used to produce core/shell Co/ZnO nanoparticles. Selective oxidation to form the core/shell nanoparticles is accomplished both during nanoparticle formation (“in situ”) and with exposure to ambient conditions (“ex situ”). The ZnO formed in situ shows single-crystalline nature with specific orientation relationships with the Co core, while the ZnO formed ex situ is polycrystalline. Conductive atomic force microscopy is utilized to measure the electrical behavior of individual nanoparticles, and both types of core/shell nanoparticles display classic bipolar resistive switching behavior. These results highlight potential application of these nanoparticles as promising next generation nonvolatile memories and neuromorphic computational devices.