| 摘要 |
Direct growth of graphene on Co3O4(111) at 1000 K was achieved by molecular beam epitaxy from a graphite source. Auger spectroscopy shows a characteristic sp2 carbon lineshape, at average carbon coverages from 0.4-3 monolayers. Low energy electron diffraction (LEED) indicates (111) ordering of the sp2 carbon film with a lattice constant of 2.5(±0.1) Å characteristic of graphene. Six-fold symmetry of the graphene diffraction spots is observed at 0.4, 1 and 3 monolayers. The LEED data also indicate an average domain size of ~ 1800Å, and show an incommensurate interface with the Co3O4(111) substrate, where the latter exhibits a lattice constant of 2.8(±0.1). Core level photoemission shows a characteristically asymmetric C(1s) feature, with the expected 1r to 1r* satellite feature, but with a binding energy for the three monolayer film of 284.9(±0.1) eV, indicative of substantial graphene-to-oxide charge transfer. |
