Absorption kinetics of thin Al films on quasicrystalline AlPdMn

Oxygen-induced surface faceting of the threefold-symmetry surface of icosahedral AlPdMn quasicrystal

“…This is surprising since the outermost layer of the quasicrystal was not only found to consist primarily of Al but also to have a similar lateral atomic density as the Al(1 1 1) surface [15]. Further, the diffusivity of Al in the quasicrystalline matrix is much lower than in its elemental crystalline form [16,17]. It is therefore likely that the oxidation of quasicrystals leads to a new surface phenomenon, which may be related in particular to the quasiperiodic atomic ordering.…”

“…Then, a continuous Al-rich amorphous oxide growth develops, which is controlled by the outward-diffusion of Al cations towards the interface. Lüscher et al [17] have demonstrated that the diffusivity of Al in i-AlPdMn quasicrystal is enhanced along the fivefold-symmetry direction compared to the threefold-symmetry direction. We therefore propose that the difference in the Al segregation is likely to result in the formation of an amorphous oxide layer of varying thickness.…”