NdNi_4M贮氢性能和电子结构关系研究

Relation between Electronic Structures of NdNi 4M and Their Hydrogen Absorption Properties

测量了NdNi4 M(M =Cr,Mn ,Fe,Co ,Ni,Cu)的吸氢性能和晶体结构参数 ,同时采用SCF Xα SW方法 ,计算了它们的电子结构 ,并对其性能和电子结构的关系进行了分析。体系费米能附近态密度峰的变化是影响贮氢合金性能的主要因素 ;吸氢平台与费米能Ef 及电荷转移数有关 ,Ef 越低 ,替代元素得到电荷的倾向越大 ,氢化物越稳定 ,吸氢平台压越低 ;H F力与吸氢量有关 ,H F力越小 ,合金吸氢量越大。

The absorption properties and crystal parameters of NdNi 4M(M=Cr, Mn, Fe, Co, Cu) were determined, the electronic structures of alloys was calculated by using SCF X α SW method, and the relations of them was investigated. The results show that the variation of density of state near E f is the main reason which influences the properties of the hydrogen storage alloys. Not only E f but also the transition of electrons in the Ni(1) atom are correlated with the hydrogen absorption plateau pressure, and the lower the energy level of E f is, the stronger the ability of losing electrons is, the better stability of hydride and the smaller the hydrogen absorption plateau pressure are presended. H F force is related to the hydrogen absorption capacity, and the lower the H F force is, the higher the hydrogen absorption capacity are obtained.