Morphological stability of alloy thin films

Misfit stresses are known to produce a morphological instability in dislocation-free thin films. We examine the linear stability of a planar, alloy thin film, growing by a deposition flux from the vapor. The stability of the film surface is influenced by stresses generated by both compositional inhomogeneity and lattice mismatch between the film and substrate. Under certain conditions, tensile misfit strain can completely stabilize the growing film, whereas the same magnitude of compressive strain is destabilizing. We compare our results with previous theoretical and experimental work.