AN AFM STUDY OF THE TRIBOLOGICAL PROPERTIES OF NACL(100) SURFACES UNDER MOIST AIR

Water molecules in the air play a very important role in the modificat ion of the physical and chemical properties of NaCl surfaces. In this paper, we report on the dependence of the friction force between this alkali halide and a Pt-coated tip on the external load at different hu midity levels. The results clearly demonstrate that the tribological p roperties of the surface are modified by water adsorption. We also fou nd that at high humidity and below a certain threshold load, the water layer can act as a lubricant. (C) 1998 Elsevier Science B.V. All righ ts reserved.