Front and domain growth of a binary mixture in the presence of a gravitational field is studied. The interplay of bulk (and surface) diffusion mechanisms is analyzed. An equation for the evolution of interfaces is derived from a time-dependent Ginzburg-Landau equation with a concentration dependent diffusion coefficient. Scaling arguemnts on this equation give the exponents of a powerlaw growth. Numerical integrations of the Ginzburg-Landau equation corroborate the theoretical analysis.
Lacasta, A.M; Hernández-Machado, A; Sancho, J.M. Front and domain growth in the presence of gravity. "Physical Review B". vol. 48, núm. 13, p. 9418-9425.