On the formation of a phase with tenfold symmetry in amorphous Ni–Zr alloys

The splat-quenched Ni50Zr50 alloy has a rosette-shaped phase with tenfold symmetry. The structure of this phase has been interpreted (Yang, 1985) as “tenfold twins” of the orthorhombic NiZr phase. The formation and the feature of the phase with tenfold symmetry have been investigated in Ni50Zr50, Ni50−xCuxZr50 and Ni50−xCoxZr50 amorphous alloys. It was found that this phase forms first during the crystallization process. The structure comes nearer to the structure of a quasi-crystal through the influence of Cu and Co atoms.