First-principles study of the graphene/Cr₂O₃ (0001) interface

The magnetoelectric properties of Cr₂O₃ in the corundum structure (chromia) has been drawn special attention due to possible implications for the next generation of spintronics devices. Due to the presence of surface magnetization, intrinsically coupled to the antiferromagnetic order parameter and robust with respect to roughness, the magnetoelectric switching of chromia may be used to electrically control the spin-dependent transport properties of an adjacent two-dimensional (2D) channel material to design a spin transistor. Graphene is the obvious choice for the 2D channel conductor, due to its unique electronic structure and excellent match of its lattice structure to the lattice structure of the (0001) surface of chromia. In this work, we use a first-principles approach to explore the atomic, electronic, and magnetic properties of the graphene/Cr₂O₃ (0001) interface. Considering different atomic configurations of the interface, we explore the induced magnetism in graphene, driven by proximity of the chromia surface, and a possibility of its modulation by the chromia surface magnetization. We discuss an impact this induced magnetism can make on the spin-dependent transport in the 2D graphene channel and the potential for using the interface structure as a spin transistor.