The frictional mechanisms of graphite derived from a single-atom tip and a graphite flake tip are systematically studied. The frictional forces in both cases are approximately proportional to the loading force because of significant deformation of the graphite surface. For “atomic friction (single-atom tip),” the effect of water on the loading force is discussed. The deformation and effective lateral stiffness of the graphite surface under ambient conditions are evaluated using the “extended Hertz model.” A single-atom tip attached to the macroscopic tip gives interpretations of atomic resolution of frictional force maps even under high loading conditions. For “flake friction (flake tip),” the graphite flake moves on graphite such that the stacking of graphite layers is maintained. In this case, the frictional coefficient along the $\left[123¯0\right]$ direction of the graphite(0001) surface is estimated to be approximately 0.001. The anisotropy of the frictional force as a function of the pulling direction is also shown.

• Received 20 November 2003

DOI:https://doi.org/10.1103/PhysRevB.69.075420