AVS 47th International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP22
Using Surface-modified Embedded-atom-potentials to Simulate the Adsorption and Diffusion of Gold and Lead Atoms on the Au(111) Surface

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: M.C. Robinson, Trent University, Canada
Authors: M.C. Robinson, Trent University, Canada
K. De'Bell, University of New Brunswick, Canada
A.J. Slavin, Trent University, Canada
Correspondent: Click to Email
The usual embedded-atom method (EAM) typically underestimates surface energies and surface diffusion barriers on (111) surfaces. However, the EAM potentials can be modified@footnote 1@ to provide a fit to the surface energy without modifying the zero-temperature bulk properties. These modified potentials provide much more reasonable values for other surface properties. For example, they predict a surface-layer compression in agreement with that observed in the Au(111) "herringbone" reconstruction. Molecular-dynamics simulations indicate that the preferred mode of surface diffusion is incorporation of an adatom into the surface at one location with the ejection of another atom to the surface elsewhere. In the case of Pb deposited on the reconstructed Au(111) surface, they also predict an instability in the surface energy for a coverage of about 0.05 monolayers. Comparisons are made with scanning tunneling microscopy data for Pb on the Au(111) surface. Research supported by NSERC Canada. @FootnoteText@ @footnote 1@ M.I. Haftel and M.I. Rosen, Phys. Rev. B15, 4426 (1995).