Direct Imaging of Lattice Atoms and Topological Defects in Graphene Membranes

Materials Sciences Division, Lawrence Berkeley National Laboratory and Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA.
Nano Letters (Impact Factor: 13.59). 07/2008; 8(11):3582-6. DOI: 10.1021/nl801386m
Source: PubMed


We present a transmission electron microscopy investigation of graphene membranes, crystalline foils with a thickness of only 1 atom. By using aberration-correction in combination with a monochromator, 1-A resolution is achieved at an acceleration voltage of only 80 kV. The low voltage is crucial for the stability of these membranes. As a result, every individual carbon atom in the field of view is detected and resolved. We observe a highly crystalline lattice along with occasional point defects. The formation and annealing of Stone-Wales defects is observed in situ. Multiple five- and seven-membered rings appear exclusively in combinations that avoid dislocations and disclinations, in contrast to previous observations on highly curved (tube- or fullerene-like) graphene surfaces.

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