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Physical Society Colloquium
Robert W. Carpick Sandia National Laboratories* The contact between a scanning force microscope tip and a sample surface can form an ideal single asperity of nanometer dimensions, where the interaction forces can be measured with sub-nanoNewton force resolution. Studies of contact, adhesion and friction for these nano-asperities have been carried out for a variety of tips and single crystal samples, revealing new atomic-scale physical insights. The major result is the observation of proportionality between friction and true contact area for a variety of interfaces, and impressive agreement with continuum mechanics models for contact area even at the nanometer scale. New work investigating the coupling of mechanical and optical responses of organic molecules at the nanometer scale will then be presented. Using a novel combination of scanning probe microscopies, we have obtained the first observation of a nano-mechanical chromatic phase transformation. * Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.
Wednesday, January 6th 1999, 15:30 |