A New Hexagonal κ Phase of Al–Cr–Ni

A new hexagonal aluminium–chromium–nickel phase, Al_14.4Cr_3.4Ni_1.1, is described. The structure includes 12 icosahedral clusters in a unit cell, each of which consists of a transition metal (TM) atom at the center and 11 aluminium and one TM atom on the fivefold vertices of the icosahedron. Pairs of the clusters are linked along the c axis by sharing a triangular face. Two pairs of the clusters are joined by two trigonal antiprisms, constructing a column along the c axis. Six such columns are included in a unit cell and form the crystal structure. The second neighboring atoms connecting the columns are on the threefold axes of the icosahedral cluster.

-1