Graphene Spin-Valve Device Grown Epitaxially on the Ni(111) Substrate: A First Principles Study

Graphene is a promising material for spintronics due to its outstanding spin transport property. Its maximally exposed 2p z orbitals allow tuning of electronic structure toward better functionality in device applications. Because the positions of carbon atoms are commensurate with those of Ni atoms on the substrate, we design a graphene spin-valve device based on the epitaxial graphene grown on the Ni (111) surface. We explored its transport properties with non equilibrium Green function theory combined with density functional theory. We show that the device has magnetoresistance (∼110%) due to the strong spin-dependent interaction between the Ni surface and the epitaxial graphene sheet.