Electronic structure of graphene on silicon carbide intercalated with silicon and cobalt atoms

The ab initio calculations have been performed for the spin-polarized band structure of graphene on silicon carbide intercalated with cobalt and silicon atoms. The cobalt and silicon atoms are shown to be localized during intercalation between the substrate and buffer layer of carbon atoms. The subsequent silicon intercalation and the formation of cobalt silicide lead to the transition from a strong hybridization to the formation of a quasi-free two-layer graphene on the system surface due to the transformation of the buffer layer to the second graphene layer.