Structure of one-dimensional Al-Co-Ni quasicrystal studied by atomic-scaletransmission electron microscopy

The structure of a one-dimensional Al-Co-Ni quasicrystal in an Al71Co19Ni10 alloy annealed at 1100 degreesC for 11 h has been studied by atomic-scale observations of high-angle annular detector scanning transmission electron microscopy and high-resolution transmission electron microscopy. Its struct ure can be characterized as a mo-dimensional aperiodic arrangement of colum nar clusters of atoms with a decagonal section of 2.0 nm in diameter and wi th pentagonal symmetry. In the arrangement Of the atomic clusters, pairs of two lattice planes with high density of the atom ic clusters are periodica lly arrayed with an interval of about 3 nm along the one direction. The ato mic clusters with two orientations of pentagonal symmetry are randomly arra nged with no special ordering manner.