2010 Volume 8 Pages 105-111
We numerically studied the atomic-scale friction of the monolayer graphene sheet during the nanoscale peeling process by molecular mechanics simulation. The zigzag behavior appears twice in the force curve during the surface and line contacts between the graphene sheet and the graphite surface. During the surface contact, the graphene sheet takes the atomic-scale sliding motion, which exhibits the transition from the continuous to the stick-slip sliding particularly for the graphene with the armchair-type free edge. The period of the zigzag structures for the stick-slip motion in the peeling force curve nearly corresponds to the lattice period of the graphite depending on the lattice orientation and the edge structure of graphene. During the line contact, the graphene sheet also takes the stick-slip sliding motion. Comparison between armchair- and zigzag-type free edges reveals the difference of the characteristic atomic-scale sliding of the graphene sheet. These findings indicate the possibility of not only the direct observation of the atomic-scale friction of the graphene sheet at the tip/surface interface but also the identification of the lattice orientation and the edge structure of the graphene sheet. [DOI: 10.1380/ejssnt.2010.105]
