Structure and glass-forming ability of simulated Ni-Zr alloys

Binary Cu-Zr system is a representative bulk glassformer demonstrating high glass forming ability due to pronounced icosahedral local ordering. From the first glance, Ni-Zr system is the most natural object to expect the same behavior because nickel and copper are neighbours in the periodic table and have similar physicochemical properties. However, doing molecular dynamics simulations of $\rm Ni_{\alpha}Zr_{1-\alpha}$ alloys described by embedded atom model potential, we observe different behaviour. We conclude that the Ni-Zr system has the same glass-forming ability as an additive binary Lennard-Jones mixture without any chemical interaction. The structural analysis reveals that icosahedral ordering in Ni-Zr alloys is much less pronounced than that in the Cu-Zr ones. We suggest that lack of icosahedral ordering due to peculiarities of interatomic interactions is the reason of relatively poor glass-forming ability of Ni-Zr system.