Influence of ordered carbon-vacancy networks on the electronic structures and elastic properties of Nb4AlC3-x

IMR OpenIR

	Influence of ordered carbon-vacancy networks on the electronic structures and elastic properties of Nb4AlC3-x
	Zhang, Hui; Hu, Tao; Li, Zhaojin; Zhang, Yanhui; Hu, Minmin; Wang, Xiaohui; Zhou, Yanchun; Wang, XH (reprint author), Chinese Acad Sci, Shenyang Natl Lab Mat Sci, Inst Met Res, Shenyang, Peoples R China.
	2017-02-01
发表期刊	JOURNAL OF THE AMERICAN CERAMIC SOCIETY
ISSN	0002-7820
卷号	100 期号:2 页码:724-731
摘要	Carbon-vacancy-bearing Nb4AlC3-x has the best high-temperature mechanical robustness among MAX phases. The existing form of the vacancies has been long overlooked. Recently, the vacancies in Nb4AlC3-x have been identified to be ordered, establishing an ordered compound Nb12Al3C8. Here, the spatial distribution of the ordered vacancies and their influences on bonding characteristics and elastic properties are unraveled by thoroughly comparing Nb12Al3C8 and vacancy-free Nb4AlC3. In Nb12Al3C8, the carbon vacancies break only relatively weak Nb-C bonds and form ordered equilateral triangular carbon-vacancy networks (OETCVNs) to maximize the bond strengthening effect. The networks slightly shift partial and total density of states toward the Fermi energy level, and bring about a feature of de-metallization. Meanwhile, the presence of OETCVNs results in the softening of elastic modulus, decreasing of the anisotropy of Young's modulus, yet increasing that of shear modulus. These results shed lights on the carbon-vacancy ordering behavior of MAX phases, and provide an opportunity to tailor their electronic structures and elastic properties through defect engineering.; Carbon-vacancy-bearing Nb4AlC3-x has the best high-temperature mechanical robustness among MAX phases. The existing form of the vacancies has been long overlooked. Recently, the vacancies in Nb4AlC3-x have been identified to be ordered, establishing an ordered compound Nb12Al3C8. Here, the spatial distribution of the ordered vacancies and their influences on bonding characteristics and elastic properties are unraveled by thoroughly comparing Nb12Al3C8 and vacancy-free Nb4AlC3. In Nb12Al3C8, the carbon vacancies break only relatively weak Nb-C bonds and form ordered equilateral triangular carbon-vacancy networks (OETCVNs) to maximize the bond strengthening effect. The networks slightly shift partial and total density of states toward the Fermi energy level, and bring about a feature of de-metallization. Meanwhile, the presence of OETCVNs results in the softening of elastic modulus, decreasing of the anisotropy of Young's modulus, yet increasing that of shear modulus. These results shed lights on the carbon-vacancy ordering behavior of MAX phases, and provide an opportunity to tailor their electronic structures and elastic properties through defect engineering.
部门归属	[zhang, hui ; hu, tao ; li, zhaojin ; zhang, yanhui ; hu, minmin ; wang, xiaohui] chinese acad sci, shenyang natl lab mat sci, inst met res, shenyang, peoples r china ; [zhang, hui ; hu, tao ; li, zhaojin] univ chinese acad sci, beijing, peoples r china ; [hu, minmin] univ sci & technol china, sch mat sci & engn, hefei, peoples r china ; [zhou, yanchun] aerosp res inst mat & proc technol, sci & technol adv funct composite lab, beijing, peoples r china
关键词	Carbides Elastic Constants Layered Crystal Structures Max Phases Vacancies
学科领域	Materials Science, Ceramics
资助者	Youth Innovation Promotion Association; Chinese Academy of Sciences [2011152]; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund
收录类别	SCI
语种	英语
WOS记录号	WOS:000394545900032
引用统计	被引频次：15[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/321006/78313
专题	中国科学院金属研究所
通讯作者	Wang, XH (reprint author), Chinese Acad Sci, Shenyang Natl Lab Mat Sci, Inst Met Res, Shenyang, Peoples R China.
推荐引用方式 GB/T 7714	Zhang, Hui,Hu, Tao,Li, Zhaojin,et al. Influence of ordered carbon-vacancy networks on the electronic structures and elastic properties of Nb4AlC3-x[J]. JOURNAL OF THE AMERICAN CERAMIC SOCIETY,2017,100(2):724-731.
APA	Zhang, Hui.,Hu, Tao.,Li, Zhaojin.,Zhang, Yanhui.,Hu, Minmin.,...&Wang, XH .(2017).Influence of ordered carbon-vacancy networks on the electronic structures and elastic properties of Nb4AlC3-x.JOURNAL OF THE AMERICAN CERAMIC SOCIETY,100(2),724-731.
MLA	Zhang, Hui,et al."Influence of ordered carbon-vacancy networks on the electronic structures and elastic properties of Nb4AlC3-x".JOURNAL OF THE AMERICAN CERAMIC SOCIETY 100.2(2017):724-731.