Hydrides of La--Ni compounds

Hydrides of various compounds in the La-Ni system were prepared by gas absorption at temperatures from 25 to 2000C and pressures from 50 to 100 atmospheres of H2. The compositions of the resulting hydrides are: La7Ni3H21, LaNiH3.6, LaNi2H4.5, LaNi3H5, La2Ni7H10 and LaNi5H6.5. X-ray diffraction verified that LaNiH3.6 and LaNi5H6.5 are ternary compounds, while LaNi2H4.5, LaNi3H5 and La2Ni7H10 form in an amorphous state when hydrided at temperatures near 250C. La7Ni3 forms primarily LaH3 during hydrogen absorption. There were no indications of superconductivity or magnetic order down to 1.8K in any of these materials