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

摘要

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, λ-(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 λ-(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 the Zn sites.