Ideal AlMnSi quasicrystal : a structural model with icosahedral clusters
نویسندگان
چکیده
A model for Al(Si)Mn quasicrystals is proposed. It is characterized by pure quasiperiodic long range order with icosahedral symmetry. The density and concentrations fit to the experimental values. The interatomic distances are compatible with crystallographic data and compare well to the related 03B1 phase. A large number of icosahedral clusters (Mackay icosahedra) are present in the model. J. Phys. France 50 (1989) 135-146 15 JANVIER 1989, Classification Physics Abstracts 61.50E 61.55H 64.70E
منابع مشابه
Atom Clusters with Icosahedral Symmetry in Cubic Alloy Phases Related to Icosahedral Quasicrystals
Icosahedral symmetry can not be allowed to exist in crystalline phases. However, the structures of some crystalline alloy phases are characterized by packing of atom clusters with icosahedral symmetry, and their structures are considered to be closely related to the structures of icosahedral quasicrystals. For examples, a cubic α-(AlMnSi) crystalline phase with a lattice constant of 1.264 nm is...
متن کاملIcosahedral AlCuFe quasicrystal at high pressure and temperature and its implications for the stability of icosahedrite
The first natural-occurring quasicrystal, icosahedrite, was recently discovered in the Khatyrka meteorite, a new CV3 carbonaceous chondrite. Its finding raised fundamental questions regarding the effects of pressure and temperature on the kinetic and thermodynamic stability of the quasicrystal structure relative to possible isochemical crystalline or amorphous phases. Although several studies s...
متن کاملHow do quasicrystals grow?
Using molecular simulations, we show that the aperiodic growth of quasicrystals is controlled by the ability of the growing quasicrystal nucleus to incorporate kinetically trapped atoms into the solid phase with minimal rearrangement. In the system under investigation, which forms a dodecagonal quasicrystal, we show that this process occurs through the assimilation of stable icosahedral cluster...
متن کاملContinuum elastic sphere vibrations as a model for low-lying optical modes in icosahedral quasicrystals
The nearly dispersionless, so-called “optical” vibrational modes observed by inelastic neutron scattering from icosahedral Al-Pd-Mn and Zn-Mg-Y quasicrystals are found to correspond well to modes of a continuum elastic sphere that has the same diameter as the corresponding icosahedral basic units of the quasicrystal. When the sphere is considered as free, most of the experimentally found modes ...
متن کاملA Quasi-Unit Cell Model for Al-Ni-Co Ideal Quasicrystal based on Clusters with Broken 10-fold Symmetry
We have constructed a structural solution for the Al72Ni20Co8 decagonal quasicrystal based on the quasi-unit cell picture. The solution gives a significantly improved fit to experiments compared to a previous proposal by us while retaining the feature that the fundamental, repeating cluster has broken 10-fold symmetry. We present a series of arguments, including new evidence based on high-resol...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2016