Rate description in friction force microscopy

Universität Bielefeld, Fakultät für Physik - D-33615 Bielefeld, Germany

Received: 27 May 2004
Accepted: 19 July 2004

Abstract

The stick-slip motion of the tip of an AFM cantilever pulled along an atomically clean surface is studied from the point of view of rate theory. An approximate relation between the pulling velocity and the resulting time-averaged friction force is deduced. This relation is valid in the entire very wide range of cantilever spring constants, for which a rate description applies. It contains previously known analogous relations as limiting cases of low or high spring constants. The high accuracy of our new relation, as well as the overall accuracy of the rate description itself, is verified by comparison with numerical results for a spatially continuous model with realistic parameters.