X-ray Study of Phason Strains in an AlCuFeMn Decagonal Phase
Wang Yang, Tomoyo Ando, Kazuki Yamamoto
pp. 847-851
Abstract
The peak profiles, shifts, and splittings of Bragg reflections, which are inherent in the phason strain of a quasicrystal, are carefully examined using a precise powder X-ray diffraction method for a wide range of different AlCuFeMn alloys and annealing temperatures. Based on the peak-shift dependences of the Bragg reflections on the phason momentum Q⊥, two kinds of new approximant phases are identified. These phases have linear phason strains θ1 = τ−6 and θ2 = τ−5, and θ1 = τ−10 and θ2 = τ−5, corresponding to lattice spacings a = 3.814 nm and b = 2.005 nm, and a = 9.985 nm and b = 2.005 nm in the quasiperiodic plane of the orthorhombic system, respectively.