A heteroepitaxial multi-atomic-layer system of graphene and h-BN

Multi-atomic-layer systems stacked with monolayer graphene/monolayer h-BN/Ni(111) have been grown in an epitaxial manner. The graphene overlayer formation changes drastically the interfacial interaction between the h-BN layer and Ni(111). As a result, a peculiar property of the monolayer h-BN on Ni(111) changes to a bulklike one. The π-d orbital hybridization at the interface disappears. Accordingly, a metallic character of monolayer h-BN disappears, the soft TO ⊥ phonon returns to the bulk one, and the reduced lattice constant of h-BN on Ni(111) also returns to the bulk one. In contrast, the h-BN overlayer formation does not change the interface between the monolayer graphene and Ni(111). From those data, the strength order of interfacial bonds changes as follows: graphene/Ni(111) > graphene/h-BN > h-BN/Ni(111).