Annealing treatment of AB2-type hydrogen storage alloys: I. crystal structures

Abstract

Abstract As part of a study on annealing effects on AB 2 -type hydrogen storage alloys, the crystal structures of two multi-component alloys have been studied. There exist three, the C15 and C14 Laves phases and the Zr 7 Ni 10 phase in the as-cast alloys. Annealing treatment leads to a transition from a multiphase structure to a single stable Laves phase structure. The stable Laves phase type (C15 or C14) is dependent on the electron-atom ratio. It was also found that annealing treatment results in the increase of the lattice parameters of the C15 phase and the decrease of that of the C14 phase.