【摘要】 <正> SmCo₅是一种磁性很强的永磁材料。1969年,Zijlstra发现SmCo₅在室温、常压下还能可逆地吸、放氢,以后又发现与SmCo₅类似的晶体结构的金属间化合物LaNi₅也能可逆地吸、放氢,LaNi₅的贮氢密度高达每立方厘米有氢原子5.5×10²²个,而4°K固态氢的密度只有5.2×10²²原子·厘米^-3。由此可见,LaNi₅的贮氢密度与固态氢相近,这就为氢能源的开发和利用,创造了很好的前景。 SmCo₅目前已是国内外商品化的产品,LaNi₅在更多还原

【Abstract】 Procedures are developed for the determination of La³⁺ and Ni²⁺ (or Sm³⁺ and Co²⁺) in LaNi₆ （or SmCo₅） alloy. After 0.1g of the sample is decomposed by 1:1 HCl, 2g of hexamethylenetetramine are added （pH 5～6）. An excess of 0.0200M EDTA reagent and 2～3 drops of xylenol orange indicator are added and back titrated with standard Pb（Ac）₂ solution until the color changes from green to red. Then 0.5g of NaF are added and the mixture is heated. After cooling, the solution is titrated again with Pb （Ac）₂ solution to a red end point.With SmCo₅ alloy, the procedure is the same as described above, except that the mixture must be heated nearly to boiling after the addition of excess EDTA.更多还原