title: Atomically resolved imaging of highly ordered alternating fluorinated graphene.
abstract: One of the most desirable goals of graphene research is to produce ordered two-dimensional (2D) chemical derivatives of suitable quality for monolayer device fabrication. Here we reveal, by focal series exit wave reconstruction (EWR), that C2F chair is a stable graphene derivative and demonstrates pristine long-range order limited only by the size of a functionalized domain. Focal series of images of graphene and C2F chair formed by reaction with XeF2 were obtained at 80 kV in an aberration-corrected transmission electron microscope. EWR images reveal that single carbon atoms and carbon-fluorine pairs in C2F chair alternate strictly over domain sizes of at least 150 nm(2) with electron diffraction indicating ordered domains ≥ 0.16 μm(2). Our results also indicate that, within an ordered domain, functionalization occurs on one side only as theory predicts. In addition, we show that electron diffraction provides a quick and easy method for distinguishing between graphene, C2F chair and fully fluorinated stoichiometric CF 2D phases.
authors.affiliation: Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Reza J
authors.initials: RJ
authors.lastname: Kashtiban
authors.affiliation: Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: M Adam
authors.initials: MA
authors.lastname: Dyson
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: Rahul R
authors.initials: RR
authors.lastname: Nair
authors.affiliation: 1] School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK [2] Department of Physics, Faculty of Arts and Sciences, Niğde University, Niğde 51000, Turkey.
authors.forename: Recep
authors.initials: R
authors.lastname: Zan
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: Swee L
authors.initials: SL
authors.lastname: Wong
authors.affiliation: SuperSTEM Laboratory, STFC Daresbury Campus, Daresbury WA4 4AD, UK.
authors.forename: Quentin
authors.initials: Q
authors.lastname: Ramasse
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK.
authors.forename: Andre K
authors.initials: AK
authors.lastname: Geim
authors.affiliation: 1] School of Materials, The University of Manchester, Manchester M1 7HS, UK [2] Department of Physics &Energy, University of Limerick, Castletroy, Ireland.
authors.forename: Ursel
authors.initials: U
authors.lastname: Bangert
authors.affiliation: Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Sloan