Preparations and applications of Highly Concentrated Metal Hydrides

我们已经形成了高浓度的金属间化合物，以改变其电和磁性能如下：1。在此条件下可以制备Mg_2NiH_x、FeTiH_x、LaNi_5H_x和LaCo_5h_x等薄膜。在高压下，使通过闪蒸在衬底上制成的膜与氢气反应。氢化物膜对多次循环的氢化和放氢反应非常稳定. Mg_2NiH_x薄膜的吸收光谱表明其吸收边位于1.6eV附近。这与结构I的计算值（1.36eV）而不是结构II的计算值（0.8eV）一致。这是首次发现金属双金属带隙.测量了LaNi_5H_x和LaCo_5H_x薄膜的霍尔系数随氢压和温度的变化。这些物质表现出反常的霍尔效应。Ni或Co颗粒在吸氢过程中可能发生了偏析.以YCo_3为基础，用Ni或Fe部分取代Co，研制了贮氢合金，通过改变Ni或Fe的含量，可以控制贮氢合金的平衡氢压. Y（Co/Ni/Fe）_3化合物的磁性能与氢的组成密切相关。

We have formed highly concentrated metal hydrides form intermetallic compounds to modify their electrical and magnetic properties as follows:1. The films of Mg_2NiH_x, FeTiH_x, LaNi_5H_x and LaCo_5h_x can be prepared. The films which are made on glas substrates by means of flash evaporation are reacted with hydrogen at a high pressure. The hydride films are very stable against several cycles of hydriding and dehydriding reactions.2. The absorption spectrum of the Mg_2NiH_x film shows that the absorption edge is located near 1.6eV. This agrees with the calculated value for Structure I (1.36eV), rather than that for structure II (0.8eV). This measurement is the first finding about the band gap of a semiconductive metal hydride.3. The Hall coefficients of LaNi_5H_x and LaCo_5H_x films have been measured as a function of hydrogen pressure and temperature. These substances show the anomalous Hall effect. It is likely that Ni or Co particles are segragated during hydrogen absorption.4. The hydrogen absorbing alloys have been developed, which are based on YCo_3 and partially substituted substituted with Ni or Fe for Co. We can control the equilibrium hydrogen pressure by variying the Ni or Fe content.5. The magnetic properties of the hydrides of Y(Co/Ni/Fe)_3 compounds depend strongly upon hydrogen composition.