中国物理B ›› 2009, Vol. 18 ›› Issue (4): 1491-1497.doi: 10.1088/1674-1056/18/4/034

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An ab initio study of niobium (n = 2--11) clusters: structure, stability and magnetism

任凤竹, 王渊旭, 张光彪, 魏书克, 罗有华   

  1. Institute of Computational Materials Science, School of Physics and Electronics,Henan University, Kaifeng 475004, China
  • 收稿日期:2008-03-04 修回日期:2008-07-29 出版日期:2009-04-20 发布日期:2009-04-20
  • 基金资助:
    Project supported by the Program for Science {\&} Technology Innovation Talents in Universities of Henan Province, China (Grant No 2009HASTIT003), the Natural Science Foundation of Henan University, China (Grant Nos 07ZRZD005 and 07YBZR046), and the Found

An ab initio study of niobium (n = 2--11) clusters: structure, stability and magnetism

Ren Feng-Zhu(任凤竹)†, Wang Yuan-Xu(王渊旭), Zhang Guang-Biao(张光彪), Wei Shu-Ke(魏书克), and Luo You-Hua(罗有华)   

  1. Institute of Computational Materials Science, School of Physics and Electronics,Henan University, Kaifeng 475004, China
  • Received:2008-03-04 Revised:2008-07-29 Online:2009-04-20 Published:2009-04-20
  • Supported by:
    Project supported by the Program for Science {\&} Technology Innovation Talents in Universities of Henan Province, China (Grant No 2009HASTIT003), the Natural Science Foundation of Henan University, China (Grant Nos 07ZRZD005 and 07YBZR046), and the Found

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摘要： The ground-state configurations of the Nbn (n= 2--11) clusters are studied through the first-principles calculations. It is found that niobium clusters (n= 2--11) tend to form compact structures with low symmetry. The clusters with 4, 8 and 10 atoms are found to be magic and have relatively large highest occupied--lowest unoccupied molecular orbital (HOMO-LUMO) gaps. The Nbn clusters possess low magnetic moments, which exhibit an odd-even oscillational character. The analyses of calculated electronic density and population of the lowest-energy niobium clusters for n= 2, 3, 5, 7, 9, 11 show that the total magnetic moments of Nbn originate mainly from a few Nb atoms with longer spacings between them in most cases, while they are located on two Nb atoms for n= 2, 3, 5. The total magnetic moments come mainly from the 4d local moments but with the exception of the Nb5 cluster.

关键词: Nbn cluster, density functional theory, structure, stability and magnetism

Abstract: The ground-state configurations of the Nbn (n= 2--11) clusters are studied through the first-principles calculations. It is found that niobium clusters (n= 2--11) tend to form compact structures with low symmetry. The clusters with 4, 8 and 10 atoms are found to be magic and have relatively large highest occupied--lowest unoccupied molecular orbital (HOMO-LUMO) gaps. The Nbn clusters possess low magnetic moments, which exhibit an odd-even oscillational character. The analyses of calculated electronic density and population of the lowest-energy niobium clusters for n= 2, 3, 5, 7, 9, 11 show that the total magnetic moments of Nbn originate mainly from a few Nb atoms with longer spacings between them in most cases, while they are located on two Nb atoms for n= 2, 3, 5. The total magnetic moments come mainly from the 4d local moments but with the exception of the Nb5 cluster.

Key words: Nbn cluster, density functional theory, structure, stability and magnetism

中图分类号:  (Electronic and magnetic properties of clusters)

  • 36.40.Cg
36.40.Mr (Spectroscopy and geometrical structure of clusters) 36.40.Qv (Stability and fragmentation of clusters) 33.15.Kr (Electric and magnetic moments (and derivatives), polarizability, and magnetic susceptibility) 31.15.A- (Ab initio calculations)