Puckering stick-slip friction induced by a sliding nanoscale contact.
An atomic force microscope reveals that the sliding of a nanotip on a graphite surface occurs through a nanoscale stick-slip mechanism. The angle between the sliding direction and a stiff crystallographic axis determines the periodicity of the slip events defining domains of various friction properties. The experimental data are interpreted using the reaction rate theory, with the energy barrier driven by a local deformation of the surface and a thermally activated relaxation.