ATOMIC-SCALE STUDY OF DRY SLIDING FRICTION

We present a theoretical study of dry sliding friction, which has a cl ose bearing on the experiments done by using the atomic and friction f orce microscope. By performing atomic-scale calculations for the frict ion between a single atom and monoatomic infinite chain, we examined t he effect of various material parameters on the stick-slip motion. We found that the perpendicular elastic deformation of the substrate that is induced by the sliding object is crucial for the energy damping in friction. In this case, the average friction force strongly depends o n the perpendicular force constant of the substrate and the friction c onstant varies with the normal force. In particular, soft materials th at continue to be elastic for a wide range of perpendicular compressio n may exhibit a second state. As a result, the hysteresis curve in the stick-slip motion becomes anisotropic.