Mean-field theory of nucleation and growth on strained surfaces
R. Grima, J. DeGraffenreid and J.A. Venables
Phys. Rev. B (2007 Brief Report) in press
Abstract
Mean-field nucleation and growth modeling is important for
understanding various adsorbate-substrate systems, particularly in
the context of epitaxial growth. Conventional mean-field theory does
not take into account non-local interactions, but adparticles may
interact with strained islands via long range elastic interactions
mediated by the substrate. We show that recent extensions of
mean-field theory to deal with non-local interactions do not
describe such processes faithfully. Here we derive a new, generally
applicable, mean-field theory of adparticle dynamics on strained
surfaces, when interdiffusion is neglected. This approach enables us
to determine the transport coefficients from the microscopic
physics; in particular we find explicit expressions for the
diffusion coefficient and drift velocity at all positions relative
to an arbitrarily strained island. We demonstrate the role of strain
on island growth, using island strain fields that are dynamically
updated, for Ge/Si(001) parameters. This approach has important
applications in the modeling of nucleation and growth of many
nanostructures, such as metal nanoclusters, semiconductor hut
clusters and silicide nanowires.
Latest version of this document: 18th October 2007.