An ordered arrangement of columnar clusters of atoms in a rhombic quasiperiodic lattice in an Al-Ni-Co decagonal phase

摘要

We have found that the structure of an Al-Ni-Co decagonal quasicrystal, which shows a diffraction pattern with many superlattice reflections (called a 'type I superlattice'), can be described as an ordered arrangement of two kinds of atomic columnar cluster with different orientations of their pentagonal symmetry. The fundamental lattice, which is constructed by connecting the clusters, is a rhombic quasiperiodic lattice with a bond length of about 2 nm. The two kinds of cluster are placed at the lattice points in a definite manner such that the two connected clusters have different orientations.