中国物理B ›› 2012, Vol. 21 ›› Issue (5): 56601-056601.doi: 10.1088/1674-1056/21/5/056601

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Ab initio study of H and He migrations in β-phase Sc, Y, and Er hydrides

陈汝承1,杨莉1 2,代云雅1,朱自强1,彭述明3,龙兴贵3,高飞2,祖小涛1   

  1. 1. Department of Applied Physics, University of Electronic Science and Technology of China, Chengdu 610054, China;
    2. Pacific Northwest National Laboratory, P. O. Box 999, Richland WA 99352, USA;
    3. Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China
  • 收稿日期:2011-11-01 修回日期:2012-04-27 出版日期:2012-04-01 发布日期:2012-04-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 10976007), the Fundamental Research Funds for the Central Universities (Grant No. ZYGX2009J040), the Science and Technology Foundation of China Academy of Engineering Physics (Grant No. 2009A0301015), and the US Department of Energy, Office of Fusion Energy Science (under Contract DE-AC06-76RLO 1830).

Ab initio study of H and He migrations in β-phase Sc, Y, and Er hydrides

Chen Ru-Cheng(陈汝承)a), Yang Li(杨莉)ab)†, Dai Yun-Ya(代云雅)a), Zhu Zi-Qiang(朱自强)a), Peng Shu-Ming(彭述明)c), Long Xing-Gui(龙兴贵)c), Gao Fei(高飞)b)†, and Zu Xiao-Tao(祖小涛)a)   

  1. a. Department of Applied Physics, University of Electronic Science and Technology of China, Chengdu 610054, China;
    b. Pacific Northwest National Laboratory, P. O. Box 999, Richland WA 99352, USA;
    c. Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China
  • Received:2011-11-01 Revised:2012-04-27 Online:2012-04-01 Published:2012-04-01
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 10976007), the Fundamental Research Funds for the Central Universities (Grant No. ZYGX2009J040), the Science and Technology Foundation of China Academy of Engineering Physics (Grant No. 2009A0301015), and the US Department of Energy, Office of Fusion Energy Science (under Contract DE-AC06-76RLO 1830).

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摘要： Ab initio calculations based on the density functional theory have been performed to investigate the migrations of hydrogen (H) and helium (He) atoms in β -phase scandium (Sc), yttrium (Y), and erbium (Er) hydrides with three different ratios of H to metal. The results show that the migration mechanisms of H and He atoms mainly depend on the crystal structures of hydrides, but their energy barriers are affected by the host-lattice in metal hydrides. The formation energies of octahedral-occupancy H (Hoct) and tetrahedral vacancy (Vmtet) pairs are almost the same (about 1.2 eV). It is of interest to note that the migration barriers of H increase with increasing host-lattice atomic number. In addition, the results show that the favorable migration mechanism of He depends slightly on the Vmtet in the Sc hydride, but strongly on that in the Y and Er hydrides, which may account for different behaviours of initial He release from ScT2 and ErT2.

关键词: hydrogen, helium, metal hydride, ab initio calculation

Abstract: Ab initio calculations based on the density functional theory have been performed to investigate the migrations of hydrogen (H) and helium (He) atoms in β -phase scandium (Sc), yttrium (Y), and erbium (Er) hydrides with three different ratios of H to metal. The results show that the migration mechanisms of H and He atoms mainly depend on the crystal structures of hydrides, but their energy barriers are affected by the host-lattice in metal hydrides. The formation energies of octahedral-occupancy H (Hoct) and tetrahedral vacancy (Vmtet) pairs are almost the same (about 1.2 eV). It is of interest to note that the migration barriers of H increase with increasing host-lattice atomic number. In addition, the results show that the favorable migration mechanism of He depends slightly on the Vmtet in the Sc hydride, but strongly on that in the Y and Er hydrides, which may account for different behaviours of initial He release from ScT2 and ErT2.

Key words: hydrogen, helium, metal hydride, ab initio calculation

中图分类号:  (Diffusion of impurities ?)

  • 66.30.J-
88.30.rd (Inorganic metal hydrides) 71.15.Mb (Density functional theory, local density approximation, gradient and other corrections)