Structural themes in approximant and decagonal quasicrystalline phases in Albased alloys

摘要

The structure of two periodic phases in the Al-Pd-Mn system showing the importance of chemical order-ing in the formation of decagonal quasicrystalline and approximant crystalline structures is reviewed.Different descriptions of the periodic phases in terms of clusters, dense planes and pentagonal chains oftransition metals are presented. We also review a structural model for AlPdMn decagonal quasicrystalsderived from the general schematic distribution of TM existing in the approximant phases. This model isdiscussed in relation of an unique decagonal overlapping cluster in a Penrose pentagonal tiling.