A series of hybrid molecular dynamics simulations was used to study the structures, energies and structural transformations of symmetrical tilt grain boundaries l. The grain boundary comprised an array of edge dislocations, with the dislocation density increasing upon increasing the grain boundary misorientation angle. The dislocation in the zigzag-oriented grain boundary contained an edge-sharing pentagon/heptagon defect, whereas the dislocation in the armchair-oriented grain boundary contained two paired pentagon/heptagon defects. In some grain boundaries, out-of-plane buckling existed due to the presence of dislocations. In the transition region (the region between the zigzag- and armchair-oriented grain boundaries), the grain boundary structures feature complex mixtures of both zigzag and armchair grain boundaries. Also considered were the grain boundary transformations and migrations that occurred upon adding or removing carbon atoms at the grain boundaries for all of the investigated types of grain boundary.

Structure, Energy, and Structural Transformations of Graphene Grain Boundaries from Atomistic Simulations. T.H.Liu, G.Gajewski, C.Pao, C.C.Chang: Carbon, 2011, 49[7], 2306–17