Figure 4 : MD simulations representing the mechanism of cutting and the edge structure.

From: Nanotomy-based production of transferable and dispersible graphene nanostructures of controlled shape and size

Figure 4

(a) The initial set-up of the simulation consists of a graphene sheet and a diamond rod. (b) After the cutting process (along the armchair orientation of a graphene sheet), the simulation shows that the edge is straight and along the direction of cutting. (c) The zoomed-in images of the carbon-atoms at the edge (for cutting along armchair, zigzag and chiral or mixing armchair-zigzag orientations) show that the edge roughness is less than 1 nm: a consequence of the dangling bonds created during nanotomy. This is compared with an HRTEM image of a 4-layered GQD, which shows a relatively smooth edge. (d) HRTEM micrographs showing the edge crystallography of two GNRs, one nanotomed in the zigzag and the other in the armchair direction. The edge roughness for zigzag is lower than that of the armchair direction. Bar=1 nm. (e) Tensile simulations were conducted to study the graphene sheet under tensile stress along its armchair and zigzag chain directions, respectively. In both cases, zigzag-edged cracks are nucleated perpendicular to the loading direction.