Fig. 5. XRD patterns of (a) starting Mg elemental powders, at 0 h and (b) after 25 h of RBM, and the XRD pattern of MgH₂/5 wt% MG-Zr₂Pd powders obtained after 50 h of RBM is displayed in (c). XRD pattern of as-RBM MgH₂ powders obtained after 50 h of milling time is presented in Fig. S1.†.