Friction force microscopy investigation of nanostructured carbon films

Frictional properties of nanostructured carbon-based films, obtained by deposition of supersonic carbon clusters, have been investigated by friction force microscopy under ambient conditions. The experiment was performed at low loads to avoid plastic deformation and wear of materials. By analysing the load-dependent measurements acquired on samples with different composition, we deduced that the Hertzian-plus-offset model can take into account the frictional behaviour of these materials. A strong dependence of adhesive forces on the specific surface location was observed. A quantitative comparison among these films and atom-assembled carbon compounds is finally presented.