Abstract
Antimony nanoparticles grown on highly oriented pyrolytic graphite and molybdenum disulfide were used as a model system to investigate the contact-area dependence of frictional forces. This system allows one to accurately determine both the interface structure and the effective contact area. Controlled translation of the antimony nanoparticles (areas between 10 000 and ) was induced by the action of the oscillating tip in a dynamic force microscope. During manipulation, the power dissipated due to tip-sample interactions was recorded. We found that the threshold value of the power dissipation needed for translation depends linearly on the contact area between the antimony particles and the substrate. Assuming a linear relationship between dissipated power and frictional forces implies a direct proportionality between friction and contact area. Particles about in size, however, were found to show dissipation close to zero. To explain the observed behavior, we suggest that structural lubricity might be the reason for the low dissipation in the small particles, while elastic multistabilities might dominate energy dissipation in the larger particles.
- Received 3 June 2004
DOI:https://doi.org/10.1103/PhysRevB.71.085405
©2005 American Physical Society