Structural variations in local areas of an al₇₀ni₁₅fe₁₅ decagonal quasicrystal and the interpretation by the 1-nm column-pair scheme

Structural variations in local areas such as the star-shaped and butterfly-shaped tiles of a noncentrosymmetric decagonal quasicrystal of Al₇₀Ni₁₅Fe₁₅ have been investigated by using the high-angle annular dark-field scanning transmission electron microscope method. It has been demonstrated that the variations of the star-shaped and butterfly-shaped tiles in Al₇₀Ni₁₅Fe₁₅ are uniquely decomposed into the 1-nm column-pairs [Saitoh et al., J. Phys. Soc. Jpn. 68 (1999) 2886], which is the basic structural unit of the -inflated Al₁₃Co₄ approximant.