Nanomechanics of a Au-lr contact using a bidirectional atomic force microscope

Friction and indentation have been studied for a sharp Ir tip contacting a Au(111) surface at loads of ⋍10 −7N. The studies were performed using a new atomic force microscope (AFM), in which lever deflection is sensed in the directions normal and lateral to the surface simultaneously through capacitance measurement. The contact behavior varied from spot to spot on the sample. The friction was higher during unloading than during loading, for identical values of the normal load. For the lower range of loading force used, behavior is elastic. The role of nanometer-scale roughness and low level impurities are considered. © 1990, American Vacuum Society. All rights reserved.