title: Rotating Anisotropic Crystalline Silicon Nanoclusters in Graphene.
abstract: The atomic structure and dynamics of silicon nanoclusters covalently bonded to graphene are studied using aberration-corrected transmission electron microscopy. We show that as the cluster size increases to 4-10 atoms, ordered crystalline cubic phases start to emerge. Anisotropic crystals are formed due to higher stability of the Si-C bond under electron beam irradiation compared to the Si-Si bond. Dynamics of the anisotropic crystalline Si nanoclusters reveal that they can rotate perpendicular to the graphene plane, with oscillations between the two geometric configurations driven by local volume constraints. These results provide important insights into the crystalline phases of clusters of inorganic dopants in graphene at the intermediate size range between isolated single atoms and larger bulk 2D forms.
authors.affiliation: Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, U.K.
authors.forename: Qu
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Stanford Nano Shared Facilities, Stanford University , Stanford, California 94305-4045, United States.
authors.forename: Ai Leen
authors.initials: AL
authors.lastname: Koh
authors.affiliation: Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, U.K.
authors.forename: Alex W
authors.initials: AW
authors.lastname: Robertson
authors.affiliation: Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, U.K.
authors.forename: Kuang
authors.initials: K
authors.lastname: He
authors.affiliation: Department of Materials Science and Engineering, Seoul National University , Seoul 151-742, Republic of Korea.
authors.forename: Sungwoo
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, Seoul National University , Seoul 151-742, Republic of Korea.
authors.forename: Euijoon
authors.initials: E
authors.lastname: Yoon
authors.affiliation: Department of Materials Science and Engineering, Seoul National University , Seoul 151-742, Republic of Korea.
authors.forename: Gun-Do
authors.initials: GD
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305-4034, United States.
authors.forename: Robert
authors.initials: R
authors.lastname: Sinclair
authors.affiliation: Department of Materials, University of Oxford , Parks Road, Oxford OX1 3PH, U.K.
authors.forename: Jamie H
authors.initials: JH
authors.lastname: Warner
keywords: Si; TEM; atoms; dopants; graphene