Spinodal decomposition during step-flow growth

Relatively little is known about the epitaxial growth of alloys that are thermodynamically unstable. An analysis here suggests that spinodal decomposition can take place by formation of step bunches with alternating composition. This provides a possible mechanism for the spontaneous formation of superlattices during molecular beam epitaxy alloy growth. Kinetic effects reduce the degree of decomposition, relative to equilibrium. At sufficiently high growth rates, decomposition is completely suppressed. © 1997 The American Physical Society.