title: Nucleation of Graphene Layers on Magnetic Oxides: Co3O4(111) and Cr2O3(0001) from Theory and Experiment.
abstract: We report directly grown strongly adherent graphene on Co3O4(111) by carbon molecular beam epitaxy (C MBE) at 850 K and density functional theory (DFT) findings that the first graphene layer is reconstructed to fit the Co3O4surface, while subsequent layers retain normal graphene structure. This adherence to the Co3O4structure results from partial bonding of half the carbons to top oxygens of the substrate. This structure is validated by X-ray photoelectron spectroscopy and low-energy electron diffraction studies, showing layer-by-layer graphene growth with ∼0.08 electrons/carbon atom transferred to the oxide from the first graphene layer, in agreement with DFT. In contrast, for Cr2O3DFT finds no strong bonding to the surface and C MBE on Cr2O3(0001) yields only graphite formation at 700 K, with C desorption above 800 K. Thus strong graphene-to-oxide charge transfer aids nucleation of graphene on incommensurate oxide substrates and may have implications for spintronics.
authors.affiliation: Department of Chemistry, University of North Texas , 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States.
authors.forename: John
authors.initials: J
authors.lastname: Beatty
authors.affiliation: Materials and Process Simulation Center, Department of Chemistry, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Tao
authors.identifier: http://orcid.org/0000-0003-4830-177X
authors.initials: T
authors.lastname: Cheng
authors.affiliation: Department of Chemistry, University of North Texas , 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Chemistry, University of North Texas , 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States.
authors.forename: M Sky
authors.initials: MS
authors.lastname: Driver
authors.affiliation: Materials and Process Simulation Center, Department of Chemistry, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: William A
authors.identifier: http://orcid.org/0000-0003-0097-5716
authors.initials: WA
authors.lastname: Goddard
authors.affiliation: Department of Chemistry, University of North Texas , 1155 Union Circle, #305070, Denton, Texas 76203-5017, United States.
authors.forename: Jeffry A
authors.initials: JA
authors.lastname: Kelber