Analytical selection of ideal epitaxial configurations and some speculations on the occurrence of epitaxy III. Epitaxy of thin (111) f.c.c. films on (110) b.c.c. substrates by coherence

Abstract

The strains needed to attain coherence in each of four important ideal epitaxial configurations, the conditions under which they obtain and illuminating graphical displays of the results are presented. A comparative study with empirical observations supports the predicted equivalence of ideal configurations and ‘atomic row matching’. The numerical values of the configurational parameter l—relating bonding and lattice parameters—obtained by applying the theory to thin-film observations, were in satisfactory agreement, with values estimated from bulk elastic and lattice constants. Certain apparent anomalies in the observations can be qualitatively understood. The repeated occurrence of matching along the [001] direction in the (110) W surface, is not understood and suggests the need for refinement in the model and/or a more detailed serutiny of its properties.