Atomic Short-Range Order in an Al72Ni20Co8 Decagonal Quasicrystal by Anomalous-X-Ray Scattering

By anomalous-X-ray scattering, the diffuse scattering around Bragg reflections was observed in a single decagonal quasicrystal of Al72Ni20Co8, which has no phason strain. The diffuse scattering is distributed around the center of the superstructure points. Intensity modulations of the diffuse scattering occur at each incident wavelength. The contrast of diffuse scattering shows the presence of atomic short-range order (SRO) in three kinds of pair correlation functions: between Al and Ni, between Ni and Co and between Co and Al. The correlation length of the diffuse scattering is estimated to be 22.5 Å.