Regensburg 2007 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 15: Methods: Scanning Probe Techniques II
O 15.8: Vortrag
Montag, 26. März 2007, 16:00–16:15, H41
Contact area dependence of friction on the nanoscale — •Dirk Dietzel1,2, Tristan Mönninghoff2, Andre Schirmeisen2, Harald Fuchs1,2, and Udo Schwarz3 — 1Forschungszentrum Karlsruhe (FZK), Karlsruhe, Germany — 2Institute of Physics, University of Münster, Münster, Germany — 3Department of Mechanical Engineering, Yale University, New Haven, CT, USA
A promising approach to analyze the fundamentals of friction on the nanometer scale is the lateral manipulation of small adsorbed islands by atomic force microscopy. In our case, the samples under investigation were metallic islands with diameters between 50-500 nm grown by thermal evaporation of antimony on highly oriented pyrolytic graphite (HOPG). With a newly developed manipulation procedure, which relies on contact-mode AFM operation, we have a simple and straightforward technique to manipulate the islands. Thereby, the lateral force signal of the AFM cantilever gives direct and quantitative information about the additional friction forces induced by the island pushing process. Using this technique, we focused on the contact area dependence of friction forces on the nanometer scale. By pushing a large variety of islands of different sizes, we found that the system shows a very clear behaviour with a linear dependence between the friction force and the contact area, thus reinforcing Amonton's law on the nanometer scale.