Density functional study of the Au-intercalated graphene/Ni(111) surface

We have studied the effect of Au intercalation on the atomic and electronic structure of the graphene/Ni(111) surface by using density functional theory calculations. Our calculations demonstrate that (1) Au atoms energetically favor interface intercalation over surface adsorption, (2) Au intercalation drastically changes the electronic structure of graphene/Ni(111) so that the graphene pi bands almost recover the Dirac cone of ideal free-standing graphene, and (3) the Fermi edge locates closely at the Dirac point, indicating that the underlying Au/Ni(111) substrate is inert. The present theory confirms a recent experimental claim that graphene grown on Ni(111) and intercalated by one monolayer Au can be regarded as quasifree standing.