The Moiré Superstructure of Graphene Intercalated with a Co Layer*

The moiré superstructure of graphene grown on metals can drive the assembly of molecular architectures, such as metal-phthalocyanine molecules, allowing for the production of artificial molecular configurations. A detailed analysis of the Gr/Co interaction upon intercalation (including the resulting moiré pattern) is performed here by density functional theory, providing an accurate description of the template as a function of the corrugation parameters. We pay special attention to the comparison with experimental photoemission data (X-ray Photoemission Spectroscopy, XPS). We then report on empty electron states in cobalt-intercalated graphene, studied by X-ray adsorption spectroscopy and angle-resolved inverse photoemission spectroscopy. The experimental data are compared with theoretical calculations to unveil the dispersion of empty states and the hybridization of graphene π bands at the Gr/Co/Ir(111) interface.