By means of high resolution electron microscopy, the hexagonal phases with
about the same c = 12.4-12.6 Angstrom but different a parameters (kappa :17
.674 Angstrom; lambda :28.382 Angstrom; upsilon :40.687 Angstrom) in Al-ric
h Al-TM (TM: transitional metal) alloys were found to consist of similar ic
osahedral cluster of about 30 Angstrom in size. Using the known atomic site
s of kappa and lambda in this cluster, the crystal structure of upsilon was
solved by direct methods of X-ray diffraction analysis. Various icosahedra
l connections in this: cluster were analyzed. (C) 2000 Elsevier Science B.V
. All rights reserved.