AVS 47th International Symposium
    Surface Science Thursday Sessions
       Session SS2+NS-ThA

Paper SS2+NS-ThA10
New Aspects of Friction Force Microscopy in Ultra-high Vacuum

Thursday, October 5, 2000, 5:00 pm, Room 209

Session: Tribology and Adhesion
Presenter: R. Bennewitz, University of Basel, Switzerland
Authors: R. Bennewitz, University of Basel, Switzerland
E. Gnecco, University of Basel, Switzerland
T. Gyalog, University of Basel, Switzerland
O. Pfeiffer, University of Basel, Switzerland
Ch. Loppacher, University of Basel, Switzerland
M. Guggisberg, University of Basel, Switzerland
E. Meyer, University of Basel, Switzerland
Correspondent: Click to Email
Recent experimental results of Friction Force Microscopy in ultra-high vacuum on well defined surfaces give new insight into the atomic processes of friction. On Cu(111), atomic stick-slip behaviour was found for the first time on a metal surface. Lateral stiffness of the contact and its I(V)-characteristic indicate that a copper neck between tip and sample is dragged over the surface.@footnote 1@ The velocity dependence of atomic stick-slip processes was studied on Cu(111) and on NaCl(100) revealing a logarithmic increase of the friction with increasing scan velocity.@footnote 2@ This dependence can be explained by introducing the effects of thermal activation into the Tomlinson model for atomic friction. A new experimental approach to study dissipation processes on atomic scale is the measurement of the damping of vertical and horizontal tip oscillations in the non-contact mode, where power losses of the order of 100 meV per tip osccilation can be detected. @FootnoteText@ @footnote 1@ R. Bennewitz et al., Phys. Rev. B60 (1999) R11301 @footnote 2@ E. Gnecco et al., Phys. Rev. Lett. 84 (2000) 1172.