First-principles calculations of LaNi4Al-H solid solution and hydrides

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	First-principles calculations of LaNi4Al-H solid solution and hydrides
	R. J. Zhang; Y. M. Wang; D. M. Chen; R. Yang; K. Yang
	2006
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	54 期号:2 页码:465-472
摘要	First-principles calculations on the crystal and electronic structures of LaNi4AlHx (x = 1, 2, 3, 4, 4.5, 5 and 7) solid solution and hydrides have been performed by employing the plane-wave pseudo-potential method. Their equilibrium structures have been determined based on the calculated relative stabilities of hydrogen occupation sites in LaNi4Al and the rule of H-H separation to be no less than 0.21 nm, as well as the full geometry optimization. The covalency and ionicity analysis shows that the interaction between H and Ni is covalent and ionic; between H and La mainly ionic; between H and Al for x = 1, 2, 3 and 4 mainly ionic and for x = 4.5, 5 and 7 both covalent and ionic. The change of BOH-Nis (or Ionicity(H-La)(s)) with x can be a phenomenological indication of the experimental phase transformation for hydrogen solubility in LaNi4Al. The comparison of the calculated stability of hydrogen at interstices in LaNi4Al and LaNi5 shows that the possible hydrogen occupation sites in LaNi4Al are fewer than those in LaNi5. This contributes to the decrease of hydrogen storage capacity for LaNi4Al, which is illustrated by comparing the electron density distribution of LaNi4AlH7 with LaNi5H7. Except for H-H repulsions, the change of absorption energy with hydrogen content,. arising from the fact that an H atom tends to keep away from an Al atom, elucidates the limited maximum hydrogen content ill LaNi4Al. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, liaoning, peoples r china. chinese acad sci, inst met res, natl engn res ctr, shenyang 110016, liaoning, peoples r china. chinese acad sci, inst met res, titanium alloys lab, shenyang 110016, peoples r china.;wang, ym (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, 72 wenhua rd, shenyang 110016, liaoning, peoples r china;ymwang@imr.ac.cn
关键词	Electronic Structure Formation Energy Hydrogen Storage Capacity Plane-wave Pseudo-potential Electronic-structure Calculations Neutron Powder Diffraction Population Analysis Intermetallic Compounds Hydrogen Absorption Lani5 Alloys Stability Energetics Storage
URL	查看原文
WOS记录号	WOS:000234785200017
引用统计	被引频次：33[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/34704
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	R. J. Zhang,Y. M. Wang,D. M. Chen,et al. First-principles calculations of LaNi4Al-H solid solution and hydrides[J]. Acta Materialia,2006,54(2):465-472.
APA	R. J. Zhang,Y. M. Wang,D. M. Chen,R. Yang,&K. Yang.(2006).First-principles calculations of LaNi4Al-H solid solution and hydrides.Acta Materialia,54(2),465-472.
MLA	R. J. Zhang,et al."First-principles calculations of LaNi4Al-H solid solution and hydrides".Acta Materialia 54.2(2006):465-472.