Decagonal quasicrystalline or microcrystalline structures: The specific case of Al-Cu-Co(-Si)

Comparing different approaches to model the atomic structure of a ternary decagonal quasicrystal

It is shown that the covering approach with a single decagonal prototile can be transformed into a hexagon, boat and star tiling. Particularly, the atomic decoration recently proposed by Cockayne and Widom (Phys. Rev. Lett. 81 (1998) 598–601) as a structure model for the decagonal phase is investigated. There, conflicts with the prototile approach arise which are due to specific peculiarities of the decoration. The above model is compared with recent experimental images which give strong support to its main features, but contradict competing structure proposals. The implications for the stabilization mechanism are discussed.

Diffuse scattering from periodic and aperiodic crystals

A (selective) review on diffuse scattering from periodic and aperiodic crystalline solids is given to demonstrate the wide field of applications in basic and applied research. After a general introduction in this field each topic is exemplified by one or two examples. Main emphasis is laid on recent work. More established work, e.g., on diffuse scattering from metals and alloys, polytypes, stacking disorder from layered structures, etc. is omitted due to the availability of excellent textbooks and reviews. Finally a short summary of recent developments of experimental methods and evaluation techniques is presented.

Twenty years of structure research on quasicrystals. Part I. Pentagonal, octagonal, decagonal and dodecagonal quasicrystals

Is quasicrystal structure analysis a never-ending story? Why is still not a single quasicrystal structure known with the same precision and reliability as structures of regular periodic crystals? What is the state-of-the-art of structure analysis of axial quasicrystals? The present comprehensive review summarizes the results of almost twenty years of structure analysis of axial quasicrystals and tries to answer these questions as far as possible. More than 2000 references have been screened for the most reliable structural models of pentagonal, octagonal, decagonal and dodecagonal quasicrystals. These models, mainly based on diffraction data and/or on bulk and surface microscopic images are critically discussed together with the limits and potentialities of the respective methods employed.