Structural and Hydrogen Storage Properties of Extremely Lightweight Compounds Synthesized from Laves Phase CaLi_2 Based System

系统地合成了用其他元素取代部分Laves相CaLi2的新系列金属间化合物。研究了它们的结构和储氢性能。我们发现了一系列新的C14型Laves相化合物，它们在室温下吸氢量高达5~7%。遗憾的是，还没有制备的样品表现出可逆的吸放氢性能。分别采用电弧法、感应熔炼法和机械球磨法合成了CaLi2和LaNi5新型复合材料。在机械球磨法制备的样品中，由于它们的X射线衍射峰仅由LaNi5的反射峰指示，因此有望发现有趣的氢化性能。在3 Mpa的氢气气氛中，分别以CaLi_2和MGH_2、SRH_2和BaH_2的混合粉末球磨制备了新的钙钛矿型氢化物。用该方法制备了结晶纯度较高的钙钛矿型氢化物SrLiH3和BaLiH3。

New series of intermetallic compounds which are replaced a part of Laves phase CaLi_2 with other elements were synthesized systematically. The structural and hydrogen storage properties of them were investigated. We found new series of C14-type Laves phase compounds which absorb much hydrogen of 5～7 mass% at room temperature. Unfortunately, no samples prepared show the reversible property of hydrogen absorbing and desorbing. Using the arc melting, the induction melting and the mechanical milling methods, respectively, new composites of CaLi_2 and LaNi_5 were synthesized. It is expected that interesting hydriding properties are found out in the samples prepared by the mechanical milling method, because the XRD pattern of them show only peaks indexed by the reflection from LaNi_5. New perovskite-type hydrides were synthesized by milling the mixed powders of CaLi_2 and MgH_2, SrH_2 and BaH_2, respectively, in a hydrogen atmosphere of 3 MPa. Perovskite-type hydrides of SrLiH_3 and BaLiH_3 with high purity crystallization were prepared by this method.