X-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 system is rhombohedral with cell parameters a = 32.16 Å and 03B1 = 36°. The space tiling problem of mean perfect icosahedral order, using only one rhombohedral cell, is discussed on the basis of some preliminary investigations in high resolution electron microscopy. J. Phys. France 51 (1990) 651-660 1er AVRIL 1990, Classification Physics Abstracts 61.55H