title: Elongated Silicon-Carbon Bonds at Graphene Edges.
abstract: We study the bond lengths of silicon (Si) atoms attached to both armchair and zigzag edges using aberration corrected transmission electron microscopy with monochromation of the electron beam. An in situ heating holder is used to perform imaging of samples at 800 °C in order to reduce chemical etching effects that cause rapid structure changes of graphene edges at room temperature under the electron beam. We provide detailed bond length measurements for Si atoms both attached to edges and also as near edge substitutional dopants. Edge reconstruction is also involved with the addition of Si dopants. Si atoms bonded to the edge of graphene are compared to substitutional dopants in the bulk lattice and reveal reduced out-of-plane distortion and bond elongation. An extended linear array of Si atoms at the edge is found to be energy-favorable due to inter-Si interactions. These results provide detailed structural information about the Si-C bonds in graphene, which may have importance in future catalytic and electronic applications.
authors.affiliation: Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: Qu
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: Alex W
authors.initials: AW
authors.lastname: Robertson
authors.affiliation: Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: Kuang
authors.initials: K
authors.lastname: He
authors.affiliation: Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: Chuncheng
authors.initials: C
authors.lastname: Gong
authors.affiliation: Department of Materials Science and Engineering, Seoul National University , Seoul 151-742, Korea.
authors.forename: Euijoon
authors.initials: E
authors.lastname: Yoon
authors.affiliation: Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: Angus I
authors.initials: AI
authors.lastname: Kirkland
authors.affiliation: Department of Materials Science and Engineering, Seoul National University , Seoul 151-742, Korea.
authors.forename: Gun-Do
authors.initials: GD
authors.lastname: Lee
authors.affiliation: Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, United Kingdom.
authors.forename: Jamie H
authors.initials: JH
authors.lastname: Warner
keywords: DFT; Si; TEM; dopants; edge; graphene