WIAS Preprint No. 1077, (2005)

Dynamic coalescence kinetics of facetted 2D islands



Authors

  • Kaganer, Vladimir
  • Ploog, Klaus
  • Sabelfeld, Karl

2010 Mathematics Subject Classification

  • 65C05

2008 Physics and Astronomy Classification Scheme

  • 81.10.Aj, 05.10.Ln, 68.43.Jk, 81.15.-z

Keywords

  • Coalescence of islands, atomic-scale Monte Carlo simulations, crystal surface, screening effect, Smoluchowski equation

Abstract

We study the coalescence of 2D islands on a crystal surface by atomic-scale kinetic Monte Carlo simulations on an ensemble of meandering islands. The Brownian motion of islands is due to the motion of atoms within the islands, with the escape of atoms from islands prohibited by the presence of a step edge barrier. We find that the diffusion of individual islands and their size distribution qualitatively change for large bond energies or low temperatures, when the islands develop straight edges (facets). The island diffusion coefficient becomes size-independent and the size distribution becomes monotonously decreasing. The results of the kinetic Monte Carlo simulations are supported by numerical solutions of the Smoluchowski equations. We derive the kernel of the Smoluchowski equations for the 2D case taking into account the screening effects and find that the screening essentially alters the island size distribution.

Appeared in

  • Phys. Rev. B., 73 (2006) pp. 115425--1--8.

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