Phase separation in amorphous Ni–Nb–Y alloys

Phase-separated amorphous Ni–Nb–Y alloys were prepared by means of rapid quenching from the melt. The microstructures change significantly with Ni content in accordance with the phase diagram. A polydisperse, heterogeneous amorphous structure is obtained for compositions with less than 60 at.% Ni lying within the two-phase liquid range. Strongly correlated chemical fluctuations in the nanometer range are observed in the amorphous alloys with more than 60 at.% Ni for which thermodynamically a homogeneous liquid should exist.