Investigation on hydrogen absorption/desorption properties of as-cast La（1-x）Mg_xNi4.25Al0.75（x=0.0, 0.1, 0.2, 0.3） alloys for tritium storage

La（（1-x））MgxNi（4.25）Al（0.75）（x = 0.0, 0.1, 0.2, 0.3）alloys for tritium storage were prepared by a method of electromagnetic induction melting. The crystal structure and hydrogen storage performance of the as-cast alloys were investigated. The results showed that a single phase of La Ni4Al was in the alloys with x = 0.0 and 0.1 and that LaNi4Al and second phase of（La,Mg）Ni）3 and AlNi3 were in the alloys with x = 0.2 and 0.3. On the other hand, the plateau pressures of P–C isotherms of the alloys were increased with the rise of the x value from 0.2 to 0.3 and the hydrogen storage capacity was obviously degraded simultaneously. It was found that the alloy had faster absorption kinetics as the proportion of Mg increased from 0.1 to 0.3.