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.

Electrochemistry of Thin Films and Nanostructured Materials

“…These methods are attracting a growing interest because they ensure low costs and scalability of materials processing, and are suitable for the production of various nanostructured materials on an industrial scale. In the bottom-up approach, individual atoms or molecules are combined into larger objects using gas phase synthesis and wet chemical methods, which include inert gas condensation [ 90 ], physical/chemical vapor condensation [ 91 ], electrodeposition [ 92 ], electroless deposition or galvanic displacement (cementation) processes [ 93 , 94 ], co-precipitation [ 95 ], sol–gel [ 96 , 97 ], solution combustion synthesis [ 98 ], hydrothermal [ 97 , 99 ], spray pyrolysis [ 100 ], thermal evaporation [ 101 ], and plasma synthesis techniques [ 102 ].…”

Large Superparamagnetic FeCo Nanocubes for Magnetic Theranostics

“…So far, neither the formation mechanism of the self-assembling NPCs nor the functional applications have been reported using a GPC technique. In contrast to conventional nanoparticle synthesis approaches (i.e., colloidal method), this GPC technique can individually control the nucleation and growth stages of nanoparticles in both time and space domains by adjusting the gas pressure, velocity, and sputtering power density. − On the other hand, it can strictly control the dimensions of spaces related to the glow discharge effect, including the cathode dark space (CDS) and negative glow (NG) region, by adjusting gas pressure, gas flow configuration, and sputtering power density. Thus, the FeCo NPCs can be synthesized by controlling the interaction between these two spaces.…”