The quasicrystal–crystal interface between icosahedral Al–Pd–Mn and deposited Co: Evidence for the affinity of the quasicrystal structure to the CsCl structure

We have evaporated Co on the pentagonal surface of an icosahedral Al–Pd–Mn quasicrystal kept at room temperature. For submonolayer Co deposits, five AlCo domains are formed exposing their (1 1 0) faces parallel to the surface and rotated by 72° with respect to each other. The orientational relationship between these domains and the substrate is determined by the optimum matching of the average quasicrystal structure and the CsCl structure with a lattice constant of about 2.88 Å. For further deposition, body-centred cubic Co domains grow epitaxially on the AlCo domains.