Regensburg 2004 – wissenschaftliches Programm
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O: Oberflächenphysik
O 14: Postersitzung (Adsorption an Oberflächen, Epitaxie und Wachstum, Organische Dünnschichten, Oxide und Isolatoren, Phasenübergänge, Rastersondentechniken, Struktur und Dynamik reiner Oberflächen)
O 14.73: Poster
Montag, 8. März 2004, 18:00–21:00, Bereich C
Temperature dependence of atomic friction on graphite — •Lars Jansen1,2, Andre Schirmeisen1,2, Hendrik Hölscher1,2, and Harald Fuchs1,2 — 1Westfälische Wilhelms Universität, Physikalisches Institut, Wilhelm-Klemm Str. 10, 48149 Münster — 2CeNTech, Center for Nanotechnology, Gievenbecker Weg 11, 48149 Münster
One fundamental mechanism of atomic scale friction is believed to be the so-called sick-slip mechanism, mathematically described by the Tomlinson model [1]. Previous investigations have shown that the temperature plays a crucial role for the velocity dependence of atomic scale friction [2]. The reason is that for finite temperatures the underlying frictional forces follow a statistical distribution.
The aim of our work is to extract these distributions from data acquired with an atomic force microscope (AFM) under ultra-high-vacuum conditions. Comparison with the ’ramped creep’ model [3] indicates good agreement with our experiments. Furthermore, we measure the temperature dependence of these distributions. As the main sample serves a vacuum cleaved HOPG-surface on which we can demonstrate the stick-slip mechanism with high resolution and good reproducibility. Measurements are performed in a temperature range from 100 K - 300 K.
[1] Tomlinson, Phil. Mag. 7, 905 (1929)
[2] Gnecco et al., Phys. Rev. Lett. 84, 1172 (2000)
[3] Sang et al., Phys. Rev. Lett. 84, 174301 (2001)