Morphology transitions at vicinal Cu surfaces based on entropic step-step interaction and diffusion along steps

An extension of the Burton-Cabrera-Frank model including diffusion along steps and entropic step-step interaction is introduced. This extended model is successfully applied to simulate recent experiments at vicinal Cu surfaces [T. Maroutian et al., Phys. Rev. Lett. 83, 4353 (1999)]. In particular, the rise of two qualitatively different morphologies can be explained by the competition of the four distinct driving and restoring forces of the model implying different directions for the growth of instabilities along the step edges. In addition, a linear stability analysis of the extended model is carried out. The result is a wavelength for the fastest growing mode which is larger than the one predicted by Bales and Zangwill and in agreement with the experiments.