Diffusional phase transformations in stressed solid films are
simulated by using an analytical solution for the elastic fields
together with a numerical solution for the composition evolution.
Isotropic and anisotropic (cubic) films are considered, where the film
is either free-standing or attached to a substrate. Stresses in the
film arise owing to both compositional self-stress and, in the
film-substrate case, misfit between the film and substrate. Stresses
are found by using analytical elastic solutions we developed for both
the two- and three-dimensional cases. Numerical simulations in both
two- and three-dimensions are performed using a Cahn-Hilliard model
for the composition evolution. Results show that elastic strength,
epitaxial misfit, elastic anisotropy, external mechanical loading and
film-substrate geometry affect both the kinetics of evolution and the
long-time metastable configurations of the evolution. In particular,
we observe phenomena such as forming of columnar structure, switching
of layers, and phase alignment in preferred directions.