F. Glas, COUPLING OF THE MORPHOLOGICAL AND COMPOSITIONAL INSTABILITIES IN A STRESSED ALLOY WITH A FREE-SURFACE, Applied surface science, 123, 1998, pp. 298-302
Citations number
17
Categorie Soggetti
Physics, Applied","Physics, Condensed Matter","Chemistry Physical","Materials Science, Coatings & Films
We give a unified thermodynamic treatment of the morphological and com
positional instabilities of a nonhydrostatically stressed alloy with a
free surface, applying in particular to lattice-mismatched semiconduc
tor epitaxial films. Provided its stress free unit cell volume depends
on composition, any such alloy is unstable with respect to a range of
joint surface undulations and composition modulations. The modulation
s of lowest energy are exponentially attenuated normally to the free s
urface. The domain of existence of the MC instability is determined as
a function of temperature and modulation wavenumber. The critical tem
perature for decomposition becomes infinite. The critical wavenumber i
s larger than for the pure morphological instability. Quantitative pre
dictions are given for various semiconductor alloys. (C) 1998 Elsevier
Science B.V.