Proximity effect induced spin filtering and gap opening in graphene by half-metallic monolayer Cr2C ferromagnet

Abstract

The idea of spin injection into graphene by proximity effect is an interesting and timely topic. Furthermore, using 2D materials to induce such an effect instead of bulk materials is a recent targeted route towards better solution for 2D spintronics. We report on first-principle calculations of the spin-dependent properties in graphene induced by its interaction with a nearby half-metallic Cr2C (2D MXene). Spin polarization can be induced in graphene by the interfacial proximity of half-metallic Cr2C ferromagnet. The average spin polarization in the graphene can reach to 74%, which is much larger than the graphene/magnetic metal or graphene/magnetic insulator heterostructures. The observed spin splitting comes from the interaction between C-pz and Cr-3d states. Except for a n-doped feature by charge transfer, the linear dispersion of Dirac cone is modified with a band gap opening of 80 meV between the bonding and antibonding states. Especially, the electronic structure, charge transfer and gap opening are shown to depend strongly on the graphene/Cr2C interlayer, which can be tailored by strain. Moreover, a strain modulated spin filter based on the graphene/Cr2C heterostructure has been proposed. These results strongly revive this novel system as a candidate for future graphene-based spintronic devices.