Structural and Compositional Changes during Hydrogenation/Dehydrogenation of the Li−Mg−N−H System

Structural and compositional changes in the Li−Mg−N−H system have been studied by probing the pressure composition isotherms at different hydrogenation/dehydrogenation stages. The results of X-ray diffractometry and Fourier transform infrared spectroscopy show that LiNH2 and a ternary imide with the composition Li2Mg2(NH)3 are reversibly formed and consumed in the hydrogen absorption/desorption processes. Chemical reactions have been proposed for hydrogen absorption and desorption, accordingly. The formation of solid solutions in the system is assumed based on structure and phase analysis.