Low-energy electron diffraction study of Xe adsorption on the ten-fold decagonal Al-Ni-Co quasicrystal surface

Abstract

The adsorption of Xe onto the tenfold surface of decagonal Al-Ni-Co was studied using low-energy electron diffraction (LEED). LEED isobar measurements indicate that Xe grows in a layer-by-layer mode for at least the first two layers in the temperature range 60\char21{}80 K. The half-monolayer isosteric heat of adsorption was measured to be $250\ifmmode\pm\else\textpm\fi{}10\mathrm{meV}.$ No superlattice was observed for the first layer of Xe, which is therefore presumed either to have a quasicrystalline structure or to be disordered. Upon adsorption of the second layer, an ordered Xe bilayer forms, which has a structure consistent with domains of bilayer Xe(111) aligned along substrate symmetry directions. At higher Xe coverages (several Xe layers), the LEED pattern becomes more distinct and remains consistent with that from a Xe(111) surface.