Compositions of Al-Based Quasicrystals Interpreted by Cluster Formulae |
| H. Chen, J.B. Qiang, Y.M. Wang and C. Dong
Key Laboratory of Materials Modification (Ministry of Education), Dalian University of Technology, Dalian 116024, China |
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| It is known previously that bulk metallic glass compositions satisfy cluster formulae [cluster](glue atom)1,3 of 24 valence electrons as deduced from our cluster-resonance model. In the present work, it is further shown that compositions of Al-based binary and ternary quasicrystals are also explained by 24-electron cluster formulae of the types [icosahedron](glue atom)0,1, where the icosahedral cluster is identified from a corresponding crystalline approximant according to dense atomic packing and cluster isolation criteria, and the glue atom site is either vacant for an icosahedral quasicrystal or equal to one for a decagonal quasicrystal. Ternary quasicrystals are formulated with the same formulae as their basic binary ones but the icosahedron shell sites are substituted by third elements. The 24-electron cluster formulae are then the chemical and electronic structural units of quasicrystals, mimicking the molecular formulae of chemical substances. |
DOI: 10.12693/APhysPolA.126.446 PACS numbers: 61.44.Br, 36.40.-c, 71.20.Lp |