S. Hayashi, B. Nowak, S. Orimo, and H. Fujii
[Journal of Alloys and Compounds, Vol.256, pp.159-165, 1997]

¹H NMR spectra and magnetization have been measured for a nanostructured Mg₂Ni-H system. ¹H MAS NMR spectra indicate the presence of four phases; alpha-Mg₂NiH_x, beta-Mg₂NiH₄, alpha-MgH_x, and beta-MgH₂, as shown in Fig. 1. Most of the hydrogens are contained in the disordered beta-Mg₂NiH₄ phase. Magnetization consists of superparamagnetic and paramagnetic ones. The former has its origin in Ni particles formed during the hydrogenation. The latter is greater than the values of crystalline alpha-Mg₂NiH_x and beta-Mg₂NiH₄. ¹H NMR line width increases with the decrease in temperature linearly, most of which is of dipolar origin. The hydrogen is more mobile in the disordered beta-Mg₂NiH₄ phase than in the crystalline counterpart.