AVS 50th International Symposium
    Surface Science Tuesday Sessions
       Session SS2-TuM

Paper SS2-TuM3
Fluctuations of Islands on Anisotropic Surfaces@footnote 1@

Tuesday, November 4, 2003, 9:00 am, Room 328

Session: Nucleation and Growth
Presenter: F. Szalma, University of Maryland, College Park
Authors: F. Szalma, University of Maryland, College Park
T.L. Einstein, University of Maryland, College Park
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We have performed kinetic Monte Carlo simulations to model the decay and edge-fluctuations of islands containing hundreds to thousands of atoms on (111) crystal surfaces. Investigating the dispersion of the Fourier modes@footnote 2@ of the fluctuations as a function of wavevector, we observe anomalous dispersion due to the geometrical fact that the equilibrium island shapes are anisotropic because of the intrinsic anisotropy of crystal surfaces. Contrary to results for the isotropic approximation,@footnote 3@ the Fourier modes are not eigenmodes of the system; however, they can be transformed into an eigensystem, which provides a means to determine the anisotropic line tension of the island. In recent experiments observing how small crystallite droplets approach their equilibrium state, these fluctuations are intimately related to their decay,@footnote 4@ and the line tension is a factor in determining their ultimate shape. Finally, comparison of theoretical and experimental configurations allows gauging of the suitability of the calculated energies used in the simulations. @FootnoteText@ @footnote 1@Work at UM supported by NSF Grants MRSEC DMR 00-80008 and EEC-0085604. FS also supported by OTKA D32835, Hungary.@footnote 2@S.V. Khare et al., Surf. Sci. 522 (2003) 75.@footnote 3@S.V. Khare and T.L. Einstein, Phys. Rev. B 54 (1996) 11752.@footnote 4@T.J. Stasevich, F. Szalma, and T.L. Einstein, submitted to SS17.