Ni(111)|Graphene|h-BN Junctions as Ideal Spin Injectors

TL;DR

This paper proposes using Ni|graphene|h-BN junctions as highly efficient spin injectors by leveraging ideal interfaces and perfect spin filtering properties, enabling customizable resistance for spintronic devices.

Contribution

It introduces a novel approach to create ideal spin injectors using Ni, graphene, and h-BN interfaces with tunable resistance-area products.

Findings

h-BN can be combined with Ni and graphene to form perfect tunnel junctions

The proposed junctions exhibit near-perfect spin filtering

Resistance-area product can be tailored for specific applications

Abstract

Deposition of graphene on top of hexagonal boron nitride (h-BN) was very recently demonstrated while graphene is now routinely grown on Ni. Because the in-plane lattice constants of graphite, h-BN, graphite-like BC2N and of the close-packed surfaces of Co, Ni and Cu match almost perfectly, it should be possible to prepare ideal interfaces between these materials which are respectively, a semimetal, insulator, semiconductor, ferromagnetic and nonmagnetic metals. Using parameter-free energy minimization and electronic transport calculations, we show how h-BN can be combined with the perfect spin filtering property of Ni|graphite and Co|graphite interfaces to make perfect tunnel junctions or ideal spin injectors (SI) with any desired resistance-area product.