Amorphous and icosahedral phase (i-phase) powders, synthesized directly by mechanical alloying (MA) and after subsequent annealing, respectively, are hydrogenated at a temperature of 573 K and an initial pressure of 3.8 MPa. The i-phase powder contains a Ti2Ni-type phase (fcc structure, lattice parameter, a = 1.23 nm) as a minor phase. Hydrogen cycling for the i-phase powder decreases the coherence length and enhances the formation of an fcc hydride phase, namely (Ti, Zr)H2. The amorphous powder, which transforms to the fcc hydride after hydrogenation, is transformed primarily into a Ti2Ni-type crystal phase and a small amount of the i-phase after hydrogen desorption. Hydrogen cycling and mechanical alloying in a hydrogen gas atmosphere dramatically reduces the loading time of hydrogen for both the i-phase and the amorphous powders.
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