LaNi_(4.5)Ga_(0.5)-H的电子结构和氢原子微观组态  

The Electronic Structure and Hydrogen Microarrangements of LaNi_(4.5)Ga_(0.5)-H Systems

作　　者：刘百超[1] 龚克[1] 陈东[1] 

机构地区：[1]信阳师范学院物理电子工程学院,河南信阳464000

出　　处：《信阳师范学院学报（自然科学版）》2008年第3期365-368,共4页Journal of Xinyang Normal University(Natural Science Edition)

基　　金：河南省教育厅自然科学研究项目(200314(X)30)

摘　　要：采用全势线性缀加平面波(FP-LAPW)方法研究了LaNi4.5Ga0.5Hy(y=1.0,1.5)的晶体结构,电子结构和氢原子的微观组态.计算基于H-H间的距离不小于2.1的准则,采用结构优化和内坐标驰豫并通过计算氢原子占据不同格位时LaNi4.5Ga0.5Hy的总能量得出氢原子最可能占据的位置.研究发现氢原子优先占据6m,12n*和3f位,4h格位没有氢原子占据.由于晶胞膨胀导致Ni-d带变窄,Ga原子的加入引起费米能级处态密度的降低,H原子的作用则相反.H和Ni,Ga之间的相互作用是LaNi4.5Ga0.5Hy固溶体保持稳定的主要因素.费米能级EF向高能区域移动的越少体系越稳定.The crystal structures, electronic structures and hydrogen occupatied sites of LaNi4.5Ga0.5Hy （y = 1.0, 1.5） have been investigated using all-electron FP-LAPW method. Their equilibrium structures have been determined based on cupation sites in LaNi4.5Ga0.5Hy and the rule of H-H the calculated relative stabilities of hydrogen ocseparation to be no less than 2.1 A, as well as the full optimization. The hydrogen atoms were found to prefer the 6m, 12n^＊ and 3f sites. A narrowed Ni-d band was found due to the lattice expansion. The Ga atom leads to a decrease of n（EF）, while the H atoms do the opposite. The interaction between Ga and Ni, H plays a dominant role in the stability of LaNi4.5Ga0.5Hy. The smaller the shift of Er towards higher energy region is, the more stable will be the compounds.

关 键 词：LaNi4.5Ga0.5 氢 电子结构 FP-LAPW方法 

分 类 号：TG139[一般工业技术—材料科学与工程]