Charla: Spatially resolved electronic structure of periodically rippled graphene

LOPEZ VAZQUEZ DE PARGA, A.; CALLEJA, F.; BORCA, B.; PASSEGGI (JR.), M.C.G.; HINAREJOS, J.J.; GUINEA, F.; MIRANDA, R.

Liverpool, United Kingdom, 27 July-1 August

Conferencia; ECOSS-25, 25th European Conference on Surface Science; 2008

European Physical Society

We report on a method to fabricate highly perfect, periodically rippled graphene monolayers and islands on Ru(0001) under ultra high vacuum conditions. The graphene layers were produced by thermal decomposition at 1000 K of ethylene molecules pre-adsorbed at 300 K on the sample surface. The epitaxial layer of graphene covers completely the surface of the single-crystal Ru substrate over distances larger than a micron and presents a triangular periodicity of 2.4 nm that is due to the coincidence lattice of graphene and Ru, i.e. the lattice of graphene has a size relation with the underlying Ru lattice that implies that 11 carbon honeycombs (0.246 nm) will adjust almost exactly with 10 Ru-Ru interatomic distances (0.27 nm). The weakly interacting, laterally undistorted graphene structure rides on top of the lattice of the substrate, resulting in some C atoms being slightly higher than others. Expuso: MIRANDA, R.