Tunneling Devices with Perpendicular Magnetic Anisotropy Electrodes on Atomically Thin van der Waals Heterostructures

TL;DR

This paper demonstrates the fabrication of perpendicular ferromagnetic electrodes on van der Waals heterostructures with enhanced anisotropy via annealing, enabling spin injection and transistor functionalities at room temperature.

Contribution

It introduces a method to create PMA electrodes on 2D heterostructures and shows their application in tunneling devices with spin injection capabilities.

Findings

PMA observed in MgO/Co/Pt on Hexagonal BN

Annealing enhances magnetic anisotropy

Devices operate at room temperature with spin injection

Abstract

We report the fabrication of perpendicular ferromagnetic electrodes for tunneling devices consist of van der Waals heterostructure. We found MgO/Co/Pt films on Hexagonal BN shows perpendicular magnetic anisotropy (PMA) with the easy axis perpendicular to the substrate. Vacuum annealing enhances the perpendicular anisotropy. The easy axis along the perpendicular direction persists up to room temperature with the Pt layer thickness ranges from 1.5 to 5 nm. We employed the PMA electrodes to construct tunneling devices on graphene and monolayer WSe2, where spin injection characteristics and field effect transistor behavior were demonstrated without strong Schottky barrier formation.