Hydride phase formation in LaMg 2Ni during H 2 absorption

Abstract

Hydrogen absorption and desorption properties in nanocrystalline LaMg 2Ni are presented. Nanostructured phases have been obtained by milling grain coarse ingot and by mechanically alloying the parent elements. The structural and hydriding properties were examined by X-ray diffraction, thermal analysis and thermal desorption measurements. Ball milling and mechanical alloying give a significant refinement of the microstructure. Reactive milling has been used for hydrogen absorption experiments. Hydrogenation by means of reactive milling at 300 K under a pressure of 0.4 MPa leads to the formation of a stable La-hydride phase together with an amorphous phase. Thermal desorption up to 983 K of hydrogenated samples leads again to parent LaMg 2Ni phase.