The structure of an Al-Ni-Co pentagonal quasicrystal studied by high-angle annular detector dark-field electron microscopy

摘要

An Al-Ni-Co pentagonal quasicrystal, showing electron diffraction patterns with pentagonal symmetry and including so-called superlattice reflections, has been examined by the high-angle annular detector dark-field technique with scanning transmission electron microscopy. Columnar clusters with a pentagonal arrangement of transition-metal atoms around their centres are arrayed in a rhombic tiling with a bond length of 2 nm, all the clusters having the same orientation of pentagonal symmetry.