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.

A molecular overlayer with the Fibonacci square grid structure.

Quasicrystals differ from conventional crystals and amorphous materials in that they possess long-range order without periodicity. They exhibit orders of rotational symmetry which are forbidden in periodic crystals, such as five-, ten-, and twelve-fold, and their structures can be described with complex aperiodic tilings such as Penrose tilings and Stampfli-Gaehler tilings. Previous theoretical work explored the structure and properties of a hypothetical four-fold symmetric quasicrystal-the so-called Fibonacci square grid.