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Summary: 1
Morphological Equilibration of Rippled and Dimpled Crystal Surfaces:
The Role of Terrace-Width Fluctuations
Jonah Erlebacher and Michael J. Aziz
Surface Science 374 (1997) 427-442
Abstract
The surface diffusion-mediated decay of unidirectional and bidirectional sinusoidal
modulations of a solid surface below its roughening temperature was studied by kinetic
Monte Carlo simulation. The characteristic decay time for bidirectional modulations with
wavelength l was found to scale as l3
, in agreement with a prediction of Rettori and
Villain and in contrast to the classical relaxation theory of Mullins for surfaces above the
roughening temperature. The characteristic decay time for unidirectional modulations
was found to have approximately the classical l4
dependence, but a different temperature
dependence. The results are explained in terms of terrace-width fluctuations and a
"terrace pinch-off" mechanism that short circuits step-step entropic repulsion as the
driving force for surface relaxation. A simple model is developed that accounts for the
temperature and wavelength dependencies of the simulation results, with no adjustable
parameters. Implications for the interpretation of experimental data are discussed.
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