Chemical vapour deposition of graphene on Ni(111) and Co(0001) and intercalation with Au to study Dirac-cone formation and Rashba splitting

We show in detail monitoring by photoelectron spectroscopy how graphene can be grown by chemical vapour deposition on the transition-metal surfaces Ni(111) and Co(0001) and intercalated by a monoatomic layer of Au. For both systems, a linear E(k) dispersion of massless Dirac fermions appears in the graphene π-band in the vicinity of the Fermi energy. In order to study ferromagnetism and spin-orbit effects by spin- and angle- resolved photoelectron spectroscopy, the sample must be magnetized in remanence. To this end, a W(110) substrate is prepared, its cleanliness verified by photoemission from W(110) surface states and surface core levels, and epitaxial Ni(111) and Co(0001) thin films are grown on top. Spin-resolved photoemission from the π-band shows that the ferromagnetic polarization of graphene/Ni(111) and graphene/Co(0001) is negligible and that graphene on Ni(111) is after intercalation of Au spin-orbit split by the Rashba effect.