Structure and Decoration of the Icosahedral and Rhombohedral Phases in AlCuFe Alloys
نویسندگان
چکیده
Structural models for Alcufe icosahedral and rhombohedral phases are obtained by decomposition, in perpendicular space, of the atomic surfaces into cells of identical local environment. The models are descnbed in 3D real space and compared to the corresponding
منابع مشابه
Icosahedral 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 کاملQUASI-CRYSTAL AND CRYSTAL IN AlMn AND AlMnSi. MODEL STRUCTURE OF THE ICOSAHEDRAL PHASE
There i s a close similari ty between the cubic a-phase in AlllnSi and the icosahedral phase i-AlllnSi or Allln. A transmission electron microscopy (T.E.14.) study of a melt-spun ribbon where the two phases coexist, establishes clearly the i r relationships. I t i s shown tha t both structures can be described with common basic unit -a double Al-lln icosahedraconnected in paralle l orientation ...
متن کاملX-ray peak broadening analysis in LaMnO3+δ nano-particles with rhombohedral crystal structure
In this work, structural and magnetic properties of LaMnO3+δ compound prepared by citrate precursor method and annealed in presence of oxygen are investigated. The structural characterization of LaMnO3+δ by X-ray powder diffraction and using X’pert package and Fullprof program is evidence for a rhombohedral structure (R-3c space group) confirmed by FTIR measurement. The magnetic measurements sh...
متن کاملمطالعه پایداری ساختاری فازهای fcc-CHX در چارچوب نظریه تابعی چگالی
Recently, a new carbon modification, namly n-diamond, have been reported, whose structure is still a matter of debate. It is important to note that the synthesis of n-diamond was carried out in the presence of hydrogen or methan. In this work we evaluate the structural stability of five fcc-CHx phases by means of first-principle calculation. The total energy is obtained as a function of the is...
متن کاملX-ray and TEM studies of Al-Fe-Cu dodecahedral particles : characterization of their microcrystalline state of pseudo-icosahedral symmetry
2014 Dodecahedral particles of Al-Fe-Cu alloy, obtained by slow solidification, have been studied by X-ray diffraction and transmission electron microscopy. Their peculiar microcrystalline structure of overall pseudo-icosahedral symmetry, previously identified by high resolution imaging and electron diffraction, is shown to be conformed by indexing of X-ray precession patterns. The crystal syst...
متن کامل