中国物理B ›› 2016, Vol. 25 ›› Issue (3): 36104-036104.doi: 10.1088/1674-1056/25/3/036104

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Energetics of carbon and nitrogen impurities and their interactions with vacancy in vanadium

Juan Hua(华娟), Yue-Lin Liu(刘悦林), Heng-Shuai Li(李恒帅),Ming-Wen Zhao(赵明文), Xiang-Dong Liu(刘向东)   

  1. 1. School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China;
    2. Department of Physics, Yantai University, Yantai 264005, China;
    3. School of Mechanical & Automotive Engineering, Liaocheng University, Liaocheng 252059, China
  • 收稿日期:2015-09-22 修回日期:2015-11-19 出版日期:2016-03-05 发布日期:2016-03-05
  • 通讯作者: Xiang-Dong Liu E-mail:xdliu@sdu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11575153 and 11375108).

Energetics of carbon and nitrogen impurities and their interactions with vacancy in vanadium

Juan Hua(华娟)1,2, Yue-Lin Liu(刘悦林)2, Heng-Shuai Li(李恒帅)1,3,Ming-Wen Zhao(赵明文)1, Xiang-Dong Liu(刘向东)1   

  1. 1. School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China;
    2. Department of Physics, Yantai University, Yantai 264005, China;
    3. School of Mechanical & Automotive Engineering, Liaocheng University, Liaocheng 252059, China
  • Received:2015-09-22 Revised:2015-11-19 Online:2016-03-05 Published:2016-03-05
  • Contact: Xiang-Dong Liu E-mail:xdliu@sdu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11575153 and 11375108).

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摘要： We studied the energetic behaviors of interstitial and substitution carbon (C)/nitrogen (N) impurities as well as their interactions with the vacancy in vanadium by first-principles simulations. Both C and N impurities prefer the octahedral site (O-site). N exhibits a lower formation energy than C. Due to the hybridization between vanadium-d and N/C-p, the N-p states are located at the energy from-6.00 eV to-5.00 eV, which is much deeper than that from-5.00 eV to-3.00 eV for the C-p states. Two impurities in bulk vanadium, C-C, C-N, and N-N can be paired up at the two neighboring O-sites along the <111> direction and the binding energies of the pairs are 0.227 eV, 0.162 eV, and 0.201 eV, respectively. Further, we find that both C and N do not prefer to stay at the vacancy center and its vicinity, but occupy the O-site off the vacancy in the interstitial lattice in vanadium. The possible physical mechanism is that C/N in the O-site tends to form a carbide/nitride-like structure with its neighboring vanadium atoms, leading to the formation of the strong C/N-vanadium bonding containing a covalent component.

关键词: vanadium, carbon/nitrogen, vacancy, first-principles

Abstract: We studied the energetic behaviors of interstitial and substitution carbon (C)/nitrogen (N) impurities as well as their interactions with the vacancy in vanadium by first-principles simulations. Both C and N impurities prefer the octahedral site (O-site). N exhibits a lower formation energy than C. Due to the hybridization between vanadium-d and N/C-p, the N-p states are located at the energy from-6.00 eV to-5.00 eV, which is much deeper than that from-5.00 eV to-3.00 eV for the C-p states. Two impurities in bulk vanadium, C-C, C-N, and N-N can be paired up at the two neighboring O-sites along the <111> direction and the binding energies of the pairs are 0.227 eV, 0.162 eV, and 0.201 eV, respectively. Further, we find that both C and N do not prefer to stay at the vacancy center and its vicinity, but occupy the O-site off the vacancy in the interstitial lattice in vanadium. The possible physical mechanism is that C/N in the O-site tends to form a carbide/nitride-like structure with its neighboring vanadium atoms, leading to the formation of the strong C/N-vanadium bonding containing a covalent component.

Key words: vanadium, carbon/nitrogen, vacancy, first-principles

中图分类号:  (Metals and alloys)

  • 61.82.Bg
71.15.Mb (Density functional theory, local density approximation, gradient and other corrections) 66.30.J- (Diffusion of impurities ?) 64.75.Bc (Solubility)