Energy dissipation in scanning force microscopy-friction on an atomic scale

Stick-slip behaviour for a typical scanning force microscope setup operated in the wearless friction regime is modelled. Not only the deflection of the cantilever but also the local elastic deformation of tip and sample are taken into account. The combined effect of macroscopic spring and microscopic elastic deformation is a key feature to the scanning motion of the tip. Within this model, energy dissipation arises naturally due to mechanical instabilities either of the macroscopic cantilever or of the microscopic tip-sample contact. Our model reproduces all features of atomically resolved friction loops, which can be calculated from interatomic potentials. Moreover, a general scheme is introduced which allows the exact response of the tip-sample system to be calculated from the different interacting potentials.