LOCAL STRUCTURES AND HYDROGEN DYNAMICS IN AMORPHOUS AND NANOSTRUCTURED MG-NI-H SYSTEMS AS STUDIED BY H-1 AND H-2 NUCLEAR-MAGNETIC-RESONANCE

H-1 and H-2 NMR spectra have been measured for amorphous MgNi-H(D) and nanostructured Mg2Ni-D systems synthesized by reactive mechanical gri nding. H-1 MAS NMR spectra indicate that the dominant phase in the amo rphous MgNi-H system is an amorphous MgNi-H phase and that a small amo unt of an amorphous/disordered alpha-MgHx phase is contained. Hydrogen s are randomly distributed in the amorphous MgNi-H phase. H-2 NMR spec tra demonstrate that hydrogen motion is faster in the order of the nan ostructured Mg2Ni-H, the crystalline Mg2NiH4 and the amorphous MgNi-H systems. (C) 1997 Elsevier Science S.A.