AVS 52nd International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP31
Friction Force Microscopy on Monolayer NaCl Films

Tuesday, November 1, 2005, 4:00 pm, Room Exhibit Hall C&D

Session: Surface Science Poster Session
Presenter: R. Bennewitz, McGill University, Canada
Authors: P. Delage, McGill University, Canada
T. Filleter, McGill University, Canada
S. Maier, McGill University, Canada
R. Bennewitz, McGill University, Canada
Correspondent: Click to Email
Friction and wear on metal surface can be greatly reduced by solid lubricant layers. We have performed Friction Force Microscopy on a model system, ultra-thin films of NaCl on a Cu(100) substrate, in order to study the microscopic mechanisms of friction in solid lubricant films. The NaCl films were grown by means of molecular evaporation in ultra-high vacuum conditions. Large islands of monolayer films are covered with nanometer-scale rectangular islands forming the subsequent layers. The decay of island density close to the edge of the film suggests a low barrier for NaCl molecules diffusing from the first monolayer to the copper substrate. In regions where the film grows over substrate terraces, islands density increases while islands size decreases. Stable friction experiments were possible even on single monolayers of NaCl, and atomic stick-slip processes have been recorded.