AVS 51st International Symposium
    Nanometer-scale Science and Technology Wednesday Sessions
       Session NS-WeA

Paper NS-WeA3
Qcm-Stm Study of the Nanotribology of Metal-Organic Interfaces

Wednesday, November 17, 2004, 2:40 pm, Room 213D

Session: Nanotribology and Nanomechanics
Presenter: S.M. Lee, North Carolina State University
Authors: S.M. Lee, North Carolina State University
M. Abdelmaksoud, North Carolina State University
J. Krim, North Carolina State University
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Energy transfer plays an important role in many surface processes such as surface diffusion, vibrational relaxation and sliding friction in adsorbed molecules.[1] The Quartz Crystal Microbalance has in recent years been employed to reveal much fundamental information on energy dissipation mechanisms associated with the sliding of atomically thin films along surfaces. While in quantitative agreement with theory and computer simulation, the QCM data have not been cross-referenced to scanning probe measurements of sliding friction and diffusive behavior of atoms along surfaces. We have thus combined a Scannning Tunneling Microscope and QCM to allow direct imaging of films adsorbed on the QCM electrode under both stationary and oscillating conditions.[2] In this study, the nano-scale frictional behavior of copper and nickel surfaces covered by various organic adsorbates (ethylene, iodobenzene, and etc.) was studied by means of STM-QCM. During the STM tip indentation, the changes in resonance frequency and amplitude of the quartz crystal were monitored simultaneously , to explore energy storage or loss mechanisms, as well as tribochemical effects, associated with tip-substrate interactions. The dependence of the frequency and the amplitude changes of each interface will be reported and interpreted in terms of the adsorbate-substrate chemical and physical interactions. Work supported by DOE, AFOSR and NSF. Reference: [1] J. Krim, Surf. Sci. 500, 741 (2002) [2] B. Borovsky, B. L. Mason, and J. Krim, J. Appl. Phys. 88, 4017 (2000).