Nano Atom Clusters and Their Long-Range Quasiperiodic Arrangements in Al-Ni-Ru Decagonal Quasicrystal

The structural features of nano-sized atom clusters and their long-rang arrangement in the Al-Ni-Ru decagonal quasicrystal with 1.6 nm periodicity have been studied and compared with those in the Al-Pd-Mn decagonal quasicrystal on the basis of electron microscopy. From the perpendicular-space analysis of the tiling obtained in a wide region, we conclude that long-range arrangement of atom clusters in the Al-Ni-Ru decagonal quasicrystal with 1.6 nm periodicity can form a Penrose-tiling-like quasiperiodic structure which is almost free of linear phase strain. In contrast, the tiling structure of the Al-Pd-Mn decagonal quasicrystal contains heavy phason strain. Our results clearly show that atom clusters formed in the Al-Ni-Ru decagonal quasicrystals and their linkage manner are completely different from those in the Al-Pd-Mn decagonal quasicrystal.