Role of Codeposited Impurities in Growth: Dependence of Morphology on Binding and Barrier Energies

The previous talk showed that codeposition of impurity atoms during epitaxial growth could be used for nanostructuring of surfaces. Based on their lateral nearest-neighbor binding energies ($E_{NN}$) to Cu and their diffusion barriers ($E_d$) on Cu(001), we classify the candidate impurity atoms into four sets. We find that codeposition of impurities from different sets produce qualitatively different surface morphologies both in the step-flow and the submonolayer ($\theta \le$ 0.7 ML) regimes. In the submonolayer regime, we characterize these differences through variations of the number of islands ($N_i$) and the average island size with coverage ($\theta$). Further, we compute the critical nucleus size ($i$) for all of these cases from the distribution of capture-zone areas using the generalized Wigner distribution.\footnote{A. Pimpinelli, T. L. Einstein, Phys. Rev. Lett. 99, 226102 (2007).}