中国物理B ›› 2016, Vol. 25 ›› Issue (3): 36601-036601.doi: 10.1088/1674-1056/25/3/036601

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

Boron diffusion in bcc-Fe studied by first-principles calculations

Xianglong Li(李向龙), Ping Wu(吴平), Ruijie Yang(杨锐杰), Dan Yan(闫丹), Sen Chen(陈森), Shiping Zhang(张师平), Ning Chen(陈宁)   

  1. 1. Department of Physics, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China;
    2. Department of Inorganic Non-metallic Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • 收稿日期:2015-08-28 修回日期:2015-11-06 出版日期:2016-03-05 发布日期:2016-03-05
  • 通讯作者: Ping Wu E-mail:pingwu@sas.ustb.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 51276016) and the National Basic Research Program of China (Grant No. 2012CB720406).

Boron diffusion in bcc-Fe studied by first-principles calculations

Xianglong Li(李向龙)1, Ping Wu(吴平)1, Ruijie Yang(杨锐杰)1, Dan Yan(闫丹)1, Sen Chen(陈森)1, Shiping Zhang(张师平)1, Ning Chen(陈宁)2   

  1. 1. Department of Physics, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China;
    2. Department of Inorganic Non-metallic Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2015-08-28 Revised:2015-11-06 Online:2016-03-05 Published:2016-03-05
  • Contact: Ping Wu E-mail:pingwu@sas.ustb.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 51276016) and the National Basic Research Program of China (Grant No. 2012CB720406).

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摘要： The diffusion mechanism of boron in bcc-Fe has been studied by first-principles calculations. The diffusion coefficients of the interstitial mechanism, the B-monovacancy complex mechanism, and the B-divacancy complex mechanism have been calculated. The calculated diffusion coefficient of the interstitial mechanism is D0 = 1.05× 10-7exp(-0.75 eV/kT)m2· s-1, while the diffusion coefficients of the B-monovacancy and the B-divacancy complex mechanisms are D1 = 1.22× 10-6f1 exp(-2.27 eV/kT) m2· s-1 and D2 ≈ 8.36× 10-6exp(-4.81 eV/kT)m2· s-1, respectively. The results indicate that the dominant diffusion mechanism in bcc-Fe is the interstitial mechanism through an octahedral interstitial site instead of the complex mechanism. The calculated diffusion coefficient is in accordance with the reported experiment results measured in Fe-3%Si-B alloy (bcc structure). Since the non-equilibrium segregation of boron is based on the diffusion of the complexes as suggested by the theory, our calculation reasonably explains why the non-equilibrium segregation of boron is not observed in bcc-Fe in experiments.

关键词: boron, diffusion coefficient, divacancy, first-principles calculation

Abstract: The diffusion mechanism of boron in bcc-Fe has been studied by first-principles calculations. The diffusion coefficients of the interstitial mechanism, the B-monovacancy complex mechanism, and the B-divacancy complex mechanism have been calculated. The calculated diffusion coefficient of the interstitial mechanism is D0 = 1.05× 10-7exp(-0.75 eV/kT)m2· s-1, while the diffusion coefficients of the B-monovacancy and the B-divacancy complex mechanisms are D1 = 1.22× 10-6f1 exp(-2.27 eV/kT) m2· s-1 and D2 ≈ 8.36× 10-6exp(-4.81 eV/kT)m2· s-1, respectively. The results indicate that the dominant diffusion mechanism in bcc-Fe is the interstitial mechanism through an octahedral interstitial site instead of the complex mechanism. The calculated diffusion coefficient is in accordance with the reported experiment results measured in Fe-3%Si-B alloy (bcc structure). Since the non-equilibrium segregation of boron is based on the diffusion of the complexes as suggested by the theory, our calculation reasonably explains why the non-equilibrium segregation of boron is not observed in bcc-Fe in experiments.

Key words: boron, diffusion coefficient, divacancy, first-principles calculation

中图分类号:  (Diffusion of impurities ?)

  • 66.30.J-
61.72.J- (Point defects and defect clusters) 61.72.S- (Impurities in crystals) 75.50.Bb (Fe and its alloys)