Regensburg 2019 – scientific programme

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O: Fachverband Oberflächenphysik

O 17: Poster Monday: 2D Materials

O 17.3: Poster

Monday, April 1, 2019, 17:45–20:00, Poster F

Atomistic simulations of chemical graphene exfoliation and carbon nanotube synthesis and of extended defects in bilayer graphene — •Florian Wullschläger, Robert Maidl, Konstantin Weber, and Bernd Meyer — Interdisciplinary Center for Molecular Materials and Computer-Chemistry-Center, FAU Erlangen-Nürnberg

Results of three recent molecular dynamics (MD) and density functional theory (DFT) studies on graphene and carbon nanotubes (CNTs) will be presented. Reductive graphite intercalation with alkali metals and subsequent dispersion in tetrahydrofuran (THF) leads to an almost complete exfoliation of graphite into graphene monolayers. The properties of the exfoliation product in liquid THF have been investigated by force-field MD simulations and first insights into role of different alkali metals in the exfoliation process will be given. Second, with force field and DFT calculations we identified the crucial reaction step in the on-surface synthesis of CNTs with controllable and defined chirality by rolling-up appropriate precursor molecules via cyclo-dehydrogenation reactions. Finally, by using a specifically adapted registry-dependent interlayer potential we show that the properties of dislocations in quasi-2D crystals, i.e. bilayer graphene, differ significantly from their 3D counterparts [1]. In addition to an in-depth structural characterization of 2D dislocations, first results on the dislocation structure in twisted graphene bilayers will be given.

[1] B. Butz, C. Dolle, F. Niekiel, K. Weber, D. Waldmann, H.B. Weber, B. Meyer, E. Spiecker, Nature 505 (2014) 533.