Influence of differences in orientational planar density on the growth of Pb on the i-Ag-In-Yb quasicrystal

Metal adsorption upon the 3-fold and 5-fold symmetric surfaces of the i-Ag–In–Yb quasicrystal has led to the observation of unique growth modes. Here, we present a study of the growth of Pb upon the 2-fold i-Ag–In–Yb surface, where the growth mechanism is found to be different from those observed on the other, higher symmetry surfaces of the same system. Initial Pb atoms occupy non-chemically-specific surface sites before forming a row structure. At higher coverages, the Pb atoms form a dense wetting layer before 1D Pb chains of limited size are self-assembled as a second layer. We therefore consider the Pb atoms to exhibit a type of Stranski–Krastanov growth mode. Substrate–adsorbate interaction is favoured in the wetting layer, before adsorbate–adsorbate interaction promotes chain growth. The difference in growth modes upon the three high symmetry surfaces is discussed with respect to their respective atomic densities