AVS 49th International Symposium
    Surface Science Thursday Sessions
       Session SS+EL-ThM

Paper SS+EL-ThM8
Scanning Force Microscopy Measurements on Ionic Crystals at Low Temperatures and Comparison to Atomistic Simulations

Thursday, November 7, 2002, 10:40 am, Room C-110

Session: Structure of Semiconductor Surfaces & Interfaces
Presenter: R. Hoffmann, University of Basel, Switzerland
Authors: R. Hoffmann, University of Basel, Switzerland
M.A. Lantz, University of Basel, Switzerland
L.N. Kantorovich, University College London, UK
A. Baratoff, University of Basel, Switzerland
H.J. Hug, University of Basel, Switzerland
A.L. Shluger, University College London, UK
H.-J. Güntherodt, University of Basel, Switzerland
Correspondent: Click to Email
Alkali halide surfaces were the first insulating materials to be imaged by scanning force microscopy (SFM) with true atomic resolution. Although atomic resolution images on alkali halides have been obtained by several groups, the tip-sample interaction above specific sites has so far been studied only theoretically.@footnote 1@ Knowing this interaction force provides insight into atomic resolution image mechanisms and allows to study bonding interactions on a surface on the atomic scale. Recently, site-specific force-distance experiments have been performed for the first time at low temperatures on the Si(111) 7x7 surface.@footnote 2@ Here we report similar measurements on the KBr (001) and the NaCl (001) surface in which we study the interaction forces and the imaging mechanism. The short-range forces have been calculated using atomistic simulations. The magnitude of the calculated forces agrees well with the experimental data, although for KBr the calculated corrugation is larger than the measured one even when the long-range forces are included. For NaCl also the corrugation is in good agreement to the experiment. @FootnoteText@ @footnote 1@ L. N. Kantorovich et al. Surf. Sci. 445, 283 (2000) @footnote 2@ M. A. Lantz et al. Science 291, 2580 (2001)