| Full text | |
| Author(s): |
Granato‚ E.
;
Ying‚ SC
Total Authors: 2
|
| Document type: | Journal article |
| Source: | TRIBOLOGY LETTERS; v. 39, n. 3, p. 229-233, 2010. |
| Abstract | |
We study the velocity dependence of the frictional force of the tip of an atomic force microscope as it is dragged across a surface, taking into account memory effects and thermal fluctuations. Memory effects are described by a coupling of the tip to low frequency excitation modes of the surface in addition to the coupling to the periodic corrugation potential. We find that when the excitation mode frequency is comparable to the characteristic frequency corresponding to the motion of the tip across the surface, the velocity dependence of the frictional force is non-monotonic, displaying a velocity range where the frictional force can decrease with increasing velocity. These results provide theoretical support for the interpretation of recent experiments which find a frictional force that decreases with velocity on surfaces covered with a monolayer. (AU) | |
| FAPESP's process: | 07/08492-9 - Dynamics, topological defects and phase transitions in ordered media |
| Grantee: | Enzo Granato |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 09/01942-4 - See Chen Ying | Brown University - Estados Unidos |
| Grantee: | Enzo Granato |
| Support Opportunities: | Research Grants - Visiting Researcher Grant - International |