Pressure-induced structural transition and thermodynamic properties of NbN and effect of metallic bonding on its hardness

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	Pressure-induced structural transition and thermodynamic properties of NbN and effect of metallic bonding on its hardness
	Z. H. Wang; X. Y. Kuang; X. F. Huang; P. Lu; A. J. Mao
	2010
发表期刊	Epl
ISSN	0295-5075
卷号	92 期号:5
摘要	Using first- principles calculations, the elastic constants, thermodynamic properties and structural phase transition of NbN under high pressure are investigated by means of the pseudopotential plane- waves method, in addition to the effect of metallic bonding on its hardness. Three candidate structures are chosen to investigate NbN, namely, rocksalt (NaCl), NiAs and WC types. On the basis of the third- order Birch- Murnaghan equation of states, the transition pressure Pt (Pt = 200.64GPa) between the WC phase and the NaCl phase of NbN is predicted for the first time. Elastic constants, formation enthalpies, shear modulus, Young's modulus, and Poisson's ratio of NbN are derived. The calculated results are found to be in good agreement with the available experimental data and theoretical values. According to the quasi-harmonic Debye model, the Debye temperature under high pressure is derived from the average sound velocity. Moreover, the effect of metallic bonding on the hardness of NbN is investigated and the hardness shows a gradual decrease rather than increase under compression. This is a quantitative investigation on the structural and thermodynamic properties of NbN, and it still awaits experimental confirmation. Copyright (C) EPLA, 2010
部门归属	[wang, zhen-hua; kuang, xiao-yu; lu, peng; mao, ai-jie] sichuan univ, inst atom & mol phys, chengdu 610065, peoples r china. [kuang, xiao-yu] acad sinice, int ctr mat phys, shenyang 110016, peoples r china. [huang, xiao-fen] sichuan normal univ, dept phys, chengdu 610068, peoples r china.;wang, zh (reprint author), sichuan univ, inst atom & mol phys, chengdu 610065, peoples r china;scu_kxy@163.com
关键词	Mechanical-properties Superhard Materials 1st-principles Nitrides Niobium
URL	查看原文
WOS记录号	WOS:000286222700023
引用统计	被引频次：20[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/321006/31560
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Z. H. Wang,X. Y. Kuang,X. F. Huang,et al. Pressure-induced structural transition and thermodynamic properties of NbN and effect of metallic bonding on its hardness[J]. Epl,2010,92(5).
APA	Z. H. Wang,X. Y. Kuang,X. F. Huang,P. Lu,&A. J. Mao.(2010).Pressure-induced structural transition and thermodynamic properties of NbN and effect of metallic bonding on its hardness.Epl,92(5).
MLA	Z. H. Wang,et al."Pressure-induced structural transition and thermodynamic properties of NbN and effect of metallic bonding on its hardness".Epl 92.5(2010).