Metal oxide interfaces are of considerable interest since they are, for instance, important supports for dispersed metal catalysts and magnetoelectronic devices. The oxidation of aluminum single-crystals leads to the formation of thin oxide surface films, which unfortunately, do not exhibit a well-ordered structure, i.e., they are amorphous oxide layers. On the contrary, after oxidation at high temperatures, surfaces of alloys such as NiAl, Ni3Al, CoAl or FeAl consist of well-ordered Al2O3 films.
Quasicrystals (QCs) form a third state of atomic ordering besides the periodic and amorphous structures. Despite their lack of periodicity, QCs deliver sharp electron- and x-ray-diffraction patterns characteristic of long-range order and well-ordered atomic structure of the surface and the bulk. These patterns reveal rotational symmetries, such as 5-, 8-, or 10-fold, incompatible with ordinary crystals.
The oxidation of the pentagonal surface of the icosahedral (i-)AlPdMn quasicrystal was previously performed at room temperature and leads to the formation of an amorphous alumina film. Here, we present the results of the oxidation at a high temperature of the 5-fold-symmetry surface of i-AlPdMn. We observe the growth of well-ordered thin Al2O3 films on top of the quasicrystalline surface. Low-energy electron diffraction patterns recorded for these films expose characteristics of the κ- and θ-Al2O3 phases. We find the presence of five (001) domains of both phases in equal azimuthal orientation, which demonstrates the close relationship of the growing oxide layers with the quasicrystalline substrate. The lateral size of the domains is for both phases approximately 5 nm. X-ray photoelectron spectroscopy investigations on these films demonstrate the preferential oxidation of the Al atoms at high temperatu
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