Structural characteristics of a high-quality Al-Ni-Ru decagonal quasicrystal with 1.6 nm periodicity, studied by atomic-scale electron microscopy observations

摘要

We report the structural characteristics of a high-quality stable decagonal quasicrystal (D phase) with 1.6 nm periodicity, formed in Al_(75)Ni_(15)Ru_(10) alloy annealed at 890 ℃ for 24h. The tiling structure and the arrangement of transition-metal atoms (Ru and Ni) in this Al-Ni-Ru D phase have been clearly revealed by high-resolution electron microscopy (HREM) and by high-angle annular detector dark-field (HAADF) scanning transmission electron microscopy (STM) respectively. On the basis of the HREM and HAADF STM observations, the relationship between the arrangement of local structural units and the formation of the long-range quasiperiodic tiling structure is discussed.