The adsorption of pentacene molecules on the 2fold surface of the icosahedral (i)AgInYb quasicrystal (QC) has been studied using scanning tunnelling microscopy (STM). The STM images show that the molecules are arranged in rows, and aligned predominantly along the highsymmetry 5fold and 2fold axes of the surface. The row separation perpendicular to the 5fold symmetry axes is either short S = 0.79 « 0.03 nm or long L = 1.24 « 0.02 nm. The ratio between them is close to the golden mean (¸= 1.618+) and creates segments of the Fibonacci sequence. Fourier transform of the scanning tunnelling microscopy (STM) images reveal 2fold, quasicrystalline, longrange order. A comparison of the STM features with the model structure of the substrate shows that Pn molecules adsorb at Yb sites.

The 2–fold surface of the icosahedral (i-)Ag–In–Yb quasicrystal has been investigated using scanning tunnelling microscopy (STM). STM data reveals a bias-voltage dependency. At high positive bias, bright protrusions are observed. At negative bias, new protrusions appear while the size of the original protrusions decreases. The STM features at both positive and negative bias polarities can be related to atomic planes intersecting the centre of Tsai-type clusters (the building blocks of the bulk structure). The bias-dependency can be explained by a change in contribution in tunnelling current from Yb and Ag/In, as expected from density of states calculations.