title: Graphene on Ni(111): Electronic Corrugation and Dynamics from Helium Atom Scattering.
abstract: Using helium atom scattering, we have studied the structure and dynamics of a graphene layer prepared in situ on a Ni(111) surface. Graphene/Ni(111) exhibits a helium reflectivity of ∼20% for a thermal helium atom beam and a particularly small surface electron density corrugation ((0.06 ± 0.02) Å peak to peak height). The Debye-Waller attenuation of the elastic diffraction peaks of graphene/Ni(111) and Ni(111) was measured at surface temperatures between 150 and 740 K. A surface Debye temperature of θD= (784 ± 14) K is determined for the graphene/Ni(111) system and θD= (388 ± 7) K for Ni(111), suggesting that the interlayer interaction between graphene and the Ni substrate is intermediary between those for strongly interacting systems like graphene/Ru(0001) and weakly interacting systems like graphene/Pt(111). In addition we present measurements of low frequency surface phonon modes on graphene/Ni(111) where the phonon modes of the Ni(111) substrate can be clearly observed. The similarity of these findings with the graphene/Ru(0001) system indicates that the bonding of graphene to a metal substrate alters the dynamic properties of the graphene surface strongly and is responsible for the high helium reflectivity of these systems.
authors.affiliation: Cavendish Laboratory , J. J. Thompson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: Anton
authors.initials: A
authors.lastname: Tamtögl
authors.affiliation: Institut Laue-Langevin , 71 Avenue des Martyrs, 38000 Grenoble, France.
authors.forename: Emanuel
authors.initials: E
authors.lastname: Bahn
authors.affiliation: Cavendish Laboratory , J. J. Thompson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: Jianding
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Institut Laue-Langevin , 71 Avenue des Martyrs, 38000 Grenoble, France.
authors.forename: Peter
authors.initials: P
authors.lastname: Fouquet
authors.affiliation: Cavendish Laboratory , J. J. Thompson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Ellis
authors.affiliation: Cavendish Laboratory , J. J. Thompson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: William
authors.initials: W
authors.lastname: Allison