Hydride stability and hydrogen desorption characteristics in melt-spun and nanocrystallized Mg-Ni-La alloy

The hydrogen desorption properties of Mg-rich alloys are significantly improved by nanostructure formation. This effect is examined for a melt-spun and nanocrystallized Mg-Ni-La alloy by pressure-composition isotherm (PCT) and thermal desorption spectrum (TDS) measurements. This alloy exhibits fast desorption kinetics and favorable PCT characteristics with an H-capacity of similar to 4.6wt%. TDS measurements reveal a definite peak ascribable to release of hydrogen from nanoboundaries, in addition to those associated with decompositions of hydrides such as MgH(2), Mg(2)NiH(4) and LaH(3). Hydrogen transport along the nanoboundaries appears to facilitate the desorption kinetics in this alloy. (C) 2006 Elsevier B.V. All rights reserved.