Structural and hydrogen absorption/desorption properties of YNi4−xAlxMg compounds (with 0 ≤ x ≤ 1.5)

The compounds YNi4−xAlxMg with 0 ≤ x ≤ 1.5, crystallizing in the C15 structure type (MgCu4Sn-type), have been elaborated by mechanical milling and a subsequent heat treatment at 650 °C for 1 h. It was possible to synthesize the compounds YNi4−xAlxMg with x up to approximately 1.15 and the lattice parameters was in good agreement with those already reported. All the samples, excepting the YNi4Mg compound, absorbed and desorbed hydrogen reversibly and no structural change is reported after the hydrogenation. A direct relationship between the lattice parameters and the equilibrium plateau pressure was found.