Hydrogenation properties of Ni-Nb-Zr–Ta amorphous ribbons

In this paper, we present the hydrogenation properties of two compositions of Ni–Nb–Zr–Ta amorphous ribbons. The importance of the alloy composition, particularly the role of Zr, in determining the stability of the structure, hydrogenation kinetics and mechanical properties are brought out. It was observed that the partial replacement of Zr by Nb in the Ni42Nb28Zr25Ta5 amorphous alloy induced a reduction of the hydrogen absorption kinetics, a larger dilatation of the amorphous structure and a lower value of hydrogen permeability for temperature larger than 450 °C. These properties are interpreted based on the possible occupation sites of hydrogen atoms in structural models recently proposed for these Ni–Nb–Zr-based amorphous alloys.