Parallel kinetic Monte Carlo simulations of two-dimensional island coarsening.
The results of parallel kinetic Monte Carlo (KMC) simulations of island coarsening based on a bond-counting model are presented. Our simulations were carried out both as a test of and as an application of the recently developed semirigorous synchronous sublattice (SL) algorithm. By carrying out simulations over long times and for large system sizes the asymptotic coarsening behavior and scaled island-size distribution (ISD) were determined. Our results indicate that while cluster diffusion and coalescence play a role at early and intermediate times, at late times the coarsening proceeds via Ostwald ripening. In addition, we find that the asymptotic scaled ISD is significantly narrower and more sharply peaked than the mean-field theory prediction. The dependence of the scaled ISD on coverage is also studied. Our results demonstrate that parallel KMC simulations can be used to effectively extend the time scale over which realistic coarsening simulations can be carried out. In particular, for simulations of the late stages of coarsening with system size L=1600 and eight processors, a parallel efficiency larger than 80% was obtained. These results suggest that the SL algorithm is likely to be useful in the future in parallel KMC simulations of more complicated models of coarsening.
Shi
Feng
F
Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606, USA. fengshi@physics.utoledo.edu
Shim
Yunsic
Y
Amar
Jacques G
JG