Scaling analysis of surface roughness in simple models for Molecular-Beam Epitaxy

There is currently interest in simple models for molecular-beam epitaxy (MBE) which mimic the effect of thermal mobility by allowing immediate incorporation of deposited atoms at kink sites within a distance l of the deposition site. Scaling of the interface width, W, with mean film height, [h], of the form W approximately [h]beta, is analysed. Studies for a solid-on-solid geometry in d = 1 + 1 dimensions revealed a sudden transition from the T = 0 K (l = 0) behavior of beta = 1/2 to a new universality class for l greater-than-orequal-to 1 with beta = 3/8. We consider the effect of incorporating realistic adsorption-site geometries and deposition dynamics into these d = 1 + 1 MBE models. We find that beta is always less than 3/8 at T = 0 K (l = 0) due to lateral coupling, and that the effective beta increases smoothly with smaller l at least to 3/8. However, for larger l, the simple scaling of W described above breaks down in the physically relevant range of [h]. Disciplines Condensed Matter Physics | Physics Comments This is a manuscript of an article published as Kang, H. C., and J. W. Evans. "Scaling analysis of surface roughness in simple models for molecular-beam epitaxy." Surface Science 269 (1992): 784-789, doi:10.1016/ 0039-6028(92)91349-G. Posted with permission. This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/physastro_pubs/391