title: Nanomesh-Type Graphene Superlattice on Au(111) Substrate.
abstract: The adherence of graphene to various crystalline substrates often leads to a periodic out-of-plane modulation of its atomic structure due to the lattice mismatch. While, in principle, convex (protrusion) and concave (depression) superlattice geometries are nearly equivalent, convex superlattices have predominantly been observed for graphene on various metal surfaces. Here we report the STM observation of a graphene superlattice with concave (nanomesh) morphology on Au(111). DFT and molecular dynamics simulations confirm the nanomesh nature of the graphene superlattice on Au(111) and also reveal its potential origin as a surface reconstruction, consisting of the imprinting of the nanomesh morphology into the Au(111) surface. This unusual surface reconstruction can be attributed to the particularly large mobility of the Au atoms on Au(111) surfaces and most probably plays an important role in stabilizing the concave graphene superlattice. We report the simultaneous observation of both convex and concave graphene superlattices on herringbone reconstructed Au(111) excluding the contrast inversion as the origin of the observed concave morphology. The observed graphene nanomesh superlattice can provide an intriguing nanoscale template for self-assembled structures and nanoparticles that cannot be stabilized on other surfaces.
authors.affiliation: Institute for Technical Physics and Materials Science, Centre for Energy Research Konkoly Thege u. 29-33, Budapest, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Süle
authors.affiliation: Institute for Technical Physics and Materials Science, Centre for Energy Research Konkoly Thege u. 29-33, Budapest, Hungary.
authors.forename: Márton
authors.initials: M
authors.lastname: Szendrő
authors.affiliation: 2D Nanoelectronics "Lendület" Research Group, Institute for Technical Physics and Materials Science, Centre for Energy Research , Konkoly Thege u. 29-33, Budapest, Hungary.
authors.forename: Gábor Zsolt
authors.initials: GZ
authors.lastname: Magda
authors.affiliation: Center for Nanometrology, Korea Research Institute of Standards and Science , Daejeon 305-340, Republic of Korea.
authors.forename: Chanyong
authors.initials: C
authors.lastname: Hwang
authors.affiliation: 2D Nanoelectronics "Lendület" Research Group, Institute for Technical Physics and Materials Science, Centre for Energy Research , Konkoly Thege u. 29-33, Budapest, Hungary.
authors.forename: Levente
authors.initials: L
authors.lastname: Tapasztó
keywords: Graphene; nanomesh; scanning tunneling microscopy; superlattice; surface reconstruction