Electronic and magnetic properties of the graphene/RE/Ni(111) (RE: La, Yb) intercalation-like interfaces: A DFT analysis

The effect of the rare-earth (RE) metals (La and Yb) intercalation on the electronic and magnetic properties of the graphene/Ni(111) interface is studied using state-of-the-art density functional theory calculations. In both systems, the intercalation of RE leads to the dramatic decrease of the magnetic moments of the Ni-interface atoms and to the negligible moments of C-atoms in a graphene layer, compared to the parent graphene/Ni(111) system. At the same time, the significant n-doping of graphene together with a band-gap opening is observed in both cases of the RE intercalation with a position of the graphene Dirac point reaching ED-EF≈-1.53 eV. Also the large density of states is found in the vicinity of the Fermi level (EF) along the M-K direction for the graphene-derived π states which can be attributed to the joint effect of the intercalated RE and interface Ni atoms. These factors – increased density of states at EF and absence of magnetism of C-atoms in a graphene layer – indicate the possibility of the observation of the superconductive state in graphene in the considered RE-based systems, which is important for the understanding of these and other electronics effects in the graphene-based systems