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TT: Fachverband Tiefe Temperaturen

TT 46: Poster Session: Graphene (joint session O/TT)

TT 46.8: Poster

Dienstag, 13. März 2018, 18:15–20:30, Poster A

Dislocations in bilayer graphene — •Florian Wullschläger, Konstantin Weber, and Bernd Meyer — Interdisciplinary Center for Molecular Materials and Computer-Chemistry-Center, FAU Erlangen-Nürnberg

Dislocations, i.e. one-dimensional line defects, are the main carriers of plastic deformation in 3D crystalline solids. In a recent TEM study it was shown that dislocations even exist in materials as thin as two graphene layers [1]. Using atomistic simulations based on the registry-dependent potential of Kolmogorov and Crespi [2] we show that the properties of dislocations in quasi-2D crystals differ significantly from their 3D counterparts. The step components of the dislocations give rise to a pronounced buckling of the bilayer in order to release strain energy. All dislocations split into equally-spaced partials due to the absence of a stacking fault energy, a peculiar property of bilayer graphene. Finally, in 2D materials the strain energy induced by a dislocation does not diverge with sample size as in 3D, but remains finite. In addition to this structural characterization of 2D dislocations we will show first results on how dislocations move in bilayer graphene and how they are pinned at lattice defects.

[1] B. Butz, C. Dolle, F. Niekiel, K. Weber, D. Waldmann, H.B. Weber, B. Meyer, E. Spiecker, Nature 505 (2014) 533.
[2] A. Kolmogorov, V. Crespi, Phys. Rev. B 71 (2005) 235415.