Effect of surface roughness and adsorbates on superlubricity

Abstract

We study the sliding of elastic solids in adhesive contact with flat and rough interfaces. We consider the dependence of the sliding friction on the elastic modulus of the solids. For elastically hard solids with planar surfaces with incommensurate surface structures we observe extremely low friction (superlubricity), which very abruptly increases as the elastic modulus decreases. We show that even a relatively small surface roughness or a low concentration of adsorbates may completely kill the superlubricity state.

9 pages, 14 figures. Minimal changes from the previous version. This manuscript has been published as one of the 25 chapters of the book "Superlubricity", edited by A. Erdemir and J.-M. Martin, Elsevier, Amsterdam (2007)