From graphene constrictions to single carbon chains


We present an atomic-resolution observation and analysis of graphene constrictions and ribbons with sub-nanometer width. Graphene membranes are studied by imaging side spherical aberration-corrected transmission electron microscopy at 80 kV. Holes are formed in the honeycomb-like structure due to radiation damage. As the holes grow and two holes approach each other, the hexagonal structure that lies between them narrows down. Transitions and deviations from the hexagonal structure in this graphene ribbon occur as its width shrinks below one nanometer. Some reconstructions, involving more pentagons and heptagons than hexagons, turn out to be surprisingly stable. Finally, single carbon atom chain bridges between graphene contacts are observed. The dynamics are observed in real time at atomic resolution with enough sensitivity to detect every carbon atom that remains stable for a sufficient amount of time. The carbon chains appear reproducibly and in various configurations from graphene bridges, between adsorbates, or at open edges and seem to represent one of the most stable configurations that a few atomic carbon system accommodates in the presence of continuous energy input from the electron beam. Carbon is one of the most important elements that occurs in numerous allotropes, displays an exceedingly rich chemistry, and is contained in a staggering number of compounds. The two solid crystalline forms, graphite and diamond, have been known since ancient times, while the more recently discovered fullerenes [1], carbon nanotubes [2, 3] and graphene [4, 5] make up a large part of today’s nanotechnology research. Thus, a wide range of allotropes and 1 These authors contributed equally to this work. 2 Author to whom any correspondence should be addressed. New Journal of Physics 11 (2009) 083019 1367-2630/09/083019+10$30.00 © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft

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@inproceedings{Chuvilin2009FromGC, title={From graphene constrictions to single carbon chains}, author={Andrey Chuvilin and Jannik C Meyer and Gerardo Algara-Siller and U. Kaiser}, year={2009} }