ATOMIC ORDERING AND THE SURFACE-MORPHOLOGY OF THIN-FILMS

The formation of ordered phases and associated surface instabilities d uring the growth of alloy films is studied using a nonequilibrium mode l. It is shown that considerations of the epitaxial thermodynamic ener gy as well as dynamical processes at the surface lead to a coupling be tween the order parameter, the composition and the surface morphology. It is demonstrated that the stability of the growing layer against at omic ordering depends on the growth rate and that even when the surfac e-selected ordered phase is thermodynamically unstable, the system can spontaneously order. (C) 1998 American Institute of Physics. [S0003-6 951 (98)02028-2].