Influence of Stone-Wales defect on graphene friction: Pinning effect and wrinkle modification

By using molecular dynamics simulation, we reveal that Stone-Wales defect increases the friction of graphene in both the armchair and zigzag direction. The friction enhancement results from two distinctive mechanisms. One is the pinning effect between several tip bottom atoms and the heptagons. In this case, the potential barrier of heptagons is larger than hexagons, and therefore the resistance is increased when a tip atom passes above these rings. The other mechanism is that the strong resistance to out-of-plane deformation leads to higher pucker beside the defect at certain moments and thus modifies the configuration of wrinkle. This effect is dependent on the trajectory of sliding. Our study provides new insight into the atomic scale friction of defective graphene.