The effect of strain upon diffusion and nucleation was studied by applying scanning tunnelling microscopy and effective medium theory to Ag on strained and unstrained (111) surfaces. Experiments had shown that the diffusion barrier was substantially lower (0.06eV) for a pseudomorphic Ag monolayer on Pt(111), as compared with that (0.097eV) for one on Ag(111). The calculations showed that this marked effect was due to a 4.2% compressive strain of the Ag monolayer on Pt. It was shown that, in general, isotropic 2-dimensional strain (as well as its relief via dislocations) had a marked effect upon surface diffusion and nucleation in hetero-epitaxial layers.

H.Brune, K.Bromann, H.Röder, K.Kern, J.Jacobsen, P.Stoltze, K.Jacobsen, J.Nørskov: Physical Review B, 1995, 52[20], R14380-3