Graphene-Passivated Nickel as an Oxidation-Resistant Electrode for Spintronics

TL;DR

This paper introduces graphene-passivated nickel electrodes that resist oxidation and preserve spin polarization, enabling more durable and cost-effective spintronic devices through a scalable CVD process.

Contribution

It presents a novel graphene coating method for nickel electrodes that maintains spin polarization and oxidation resistance, advancing spintronics technology.

Findings

Graphene coating prevents nickel oxidation upon air exposure.

The spin polarization is preserved and can be reversed with the graphene layer.

The process is scalable and compatible with low-cost fabrication methods.

Abstract

We report on graphene-passivated ferromagnetic electrodes (GPFE) for spin devices. GPFE are shown to act as spin-polarized oxidation-resistant electrodes. The direct coating of nickel with few layer graphene through a readily scalable chemical vapour deposition (CVD) process allows the preservation of an unoxidized nickel surface upon air exposure. Fabrication and measurement of complete reference tunneling spin valve structures demonstrates that the GPFE is maintained as a spin polarizer and also that the presence of the graphene coating leads to a specific sign reversal of the magneto-resistance. Hence, this work highlights a novel oxidation-resistant spin source which further unlocks low cost wet chemistry processes for spintronics devices.