Local structures and hydrogen dynamics in amorphous and nanostructured MgNiH systems as studied by 1H and 2H nuclear magnetic resonance

Abstract

1H and 2H NMR spectra have been measured for amorphous MgNiH(D) and nanostructured Mg 2NiD systems synthesized by reactive mechanical grinding. 1H MAS NMR spectra indicate that the dominant phase in the amorphous MgNiH system is an amorphous MgNiH phase and that a small amount of an amorphous/disordered α-MgH, phase is contained. Hydrogens are randomly distributed in the amorphous MgNiH phase. 2H NMR spectra demonstrate that hydrogen motion is faster in the order of the nanostructured Mg 2NiH, the crystalline Mg 2NiH 4 and the amorphous MgNiH systems.