Synthesis of LiNH 2 films by vacuum evaporation

Abstract

LiNH 2, a new candidate of reversible hydrogen storage materials, was synthesized by vacuum evaporation of elemental Li with 99.9%-purity onto a metallic substrate, and subsequent nitrogenation and hydrogenation using high-purity gases. Depending on the evaporation time, the sample morphologies change from an island-shape with nearly 50 μm (873 K for 0 min; just heated-up to the set temperature) to a homogeneously flat film (873 K for 30 min) with a thickness of nearly 500 μm. The preliminary thermal desorption measurement implies a lower temperature hydrogen desorption from the film than that from bulk (powder) sample.