Periodic conservative component of sliding friction force for atomically-flat nanosized contact areas: dependence on misfit angle and size

To understand the periodic conservative component of sliding friction force for atomically-flat nanosized contact areas, we have investigated an interfacial potential energy surface responsible for sliding of a two-dimensional rigid atomic cluster on a periodic potential surface and moiré-like misfit dislocation net patterns in the contact area. We found that especially when the misfit parameter (ratio) α between lattice constants of the contacting surfaces is close to 1.0, the interfacial potential energy surface varies depending strongly on the lattice misfit angle θ and the size of the contact area, resulting in changes in the misfit dislocation net pattern.