Annealing treatment of AB(2)-type hydrogen storage alloys: I. crystal structures

As part of a study on annealing effects on AB(2)-type hydrogen storage allo ys, the crystal structures of two multi-component alloys have been studied. There exist three, the C15 and C14 Laves phases and the Zr7Ni10 phase in t he as-cast alloys. Annealing treatment leads to a transition from a multiph ase structure to a single stable Laves phase structure. The stable Laves ph ase 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 param eters of the C15 phase and the decrease of that of the C14 phase. (C) 1999 Elsevier Science S.A. All rights reserved.