Rietveld refinement and ab initio calculations of a C14-like Laves phase in Ti-Zr-Ni

Ternary Ti-Zr-Ni alloys form icosahedral and other complex phases near the composition Ti 41.5 Zr 41.5 Ni 17 . Among these is a C14-like Laves phase, u -(Ti-Zr-Ni), which forms at a composition Ti 37 Zr 33 Ni 30 . The crystal structure of this phase is determined by a Rietveld analysis. Ab initio calculations are used to confirm the structural details and to investigate the energetic stability of the structure. We show that u -(Ti-Zr-Ni) is a high-temperature phase, with a MgZn 2 -type structure with Zr occupying primarily the Mg sites and Ti and Ni randomly occupying the Zn sites.