Structural studies of Li3N using neutron powder diffraction

The search for alternative fuel has spurred interest in complexes with high hydrogen absorption-desorption capacities. Among these compounds complex metal hydrides have received much attention. More recently, it was proposed that simple metal nitrides such as lithium nitride (Li3N), with its 9 wt% recyclable hydrogen uptake, could be good candidates for reversible hydrogen storage. In this paper, we present the results of detailed structural study of Li3N through the temperature range 20-673 K using neutron powder diffraction. Commercially purchased compound showed a co-existence of alpha and beta phases of Li3N. We observed a steady decline of the beta phase above 473 K and a very small fraction (similar to 2.5 wt%) remained untransformed at 673 K. This transformation (beta to alpha) was not reversible on cooling. (C) 2006 Elsevier B.V. All rights reserved.