NIST logo

Publication Citation: Adhesion-dependent negative friction coefficient on chemically modified graphite at the nanoscale

NIST Authors in Bold

Author(s): Zhao Z. Deng; Alexander Y. Smolyanitsky; Qunyang Li; Xi-Qiao Feng; Rachel J. Cannara;
Title: Adhesion-dependent negative friction coefficient on chemically modified graphite at the nanoscale
Published: October 14, 2012
Abstract: A negative friction coefficient is observed for graphite using atomic force microscopy. The magnitude of the friction coefficient increases with adhesion, which we control by exposing graphite to different conditions. We demonstrate that the negative coefficient is a mechanical effect arising from changes in the bending stiffness of the top layer of graphite with applied load, and not a result of a change in atomic corrugation. We further show that the adhesive force at which the onset of this negative friction-load dependence occurs is determined by the interlayer binding energy.
Citation: Nature Materials
Volume: 11
Issue: 12
Pages: pp. 1032 - 1037
Keywords: nanoscale friction; nanoscale adhesion; graphite; interlayer binding energy; atomic force microscopy; friction force microscopy
Research Areas: Surface Physics, Measurements
DOI: http://dx.doi.org/10.1038/nmat3452  (Note: May link to a non-U.S. Government webpage)
PDF version: PDF Document Click here to retrieve PDF version of paper (2MB)