In-situ Neutron Diffraction Studies of the Hydrogen storage material Li$_{3}$N

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 (Li$_{3}$N), with its 9 wt {\%} recyclable hydrogen uptake, could be good candidates for reversible hydrogen storage. In this presentation we present the results of detailed structural study of Li$_{3}$N through the temperature range 20K to 673K using Neutron Powder Diffraction. Commercially purchased compound showed a coexistence of alpha and beta phases of Li$_{3}$N. We observed a steady decline of the beta phase above 473K and a very small fraction ($\sim $3 wt {\%}) was frozen in at 673K. This transformation ($\beta $ to $\alpha )$ was not reversible on cooling. We will also present the findings of in-situ neutron diffraction measurements of hydrogen absorption and desorption of the title material.