物理化学学报 >> 2008, Vol. 24 >> Issue (11): 1964-1968.doi: 10.3866/PKU.WHXB20081105

研究论文 上一篇    下一篇

H原子在完美δ-Pu金属体相中的扩散行为

魏洪源; 罗顺忠; 刘国平; 熊晓玲; 宋宏涛   

  1. 中国工程物理研究院, 核物理与化学研究所, 四川 绵阳 621900
  • 收稿日期:2008-07-09 修回日期:2008-08-04 发布日期:2008-11-10
  • 通讯作者: 魏洪源 E-mail:wwwhy@126.com

Hydrogen Diffusion Behavior in Perfect δ-Pu Metal

WEI Hong-Yuan; LUO Shun-Zhong; LIU Guo-Ping; XIONG Xiao-Ling; SONG Hong-Tao   

  1. Institute of Nuclear Physics and Chemistry, Chinese Academy of Engineering Physics, Mianyang 621900, Sichuan Province, P. R. China
  • Received:2008-07-09 Revised:2008-08-04 Published:2008-11-10
  • Contact: WEI Hong-Yuan E-mail:wwwhy@126.com

摘要: 采用密度泛函理论的广义梯度近似方法计算了H原子在δ-Pu金属体相中可能稳定存在间隙位置的嵌入能. 计算结果表明, 八面体间隙是H原子最稳定存在位置, 无自旋极化和自旋极化水平的嵌入能分别为-3.12和-2.22 eV. 四面体间隙位的嵌入能相对稍大, 是次稳定存在位置. 通过能量分析推测了单个H原子在完美δ-Pu金属中可能的扩散路径和扩散能垒. 最可能扩散路径为相邻不同间隙位的交替扩散, 八面体间隙到四面体间隙的扩散能垒为1.06 eV, 而四面体间隙到八面体间隙的扩散能垒为0.38 eV. 另外沿平行晶轴方向四面体间隙到四面体间隙交替直线扩散的能垒为1.83 eV, 八面体间隙到八面体间隙交替扩散路径的能垒最高, 为2.52 eV.

关键词: H原子, δ-Pu金属, 扩散行为, 密度泛函理论, 周期模型

Abstract: The diffusion behavior of hydrogen atomin perfect δ-Pu metal was studied with density functional theory (DFT) and periodical model. The stablest site for hydrogen is the octahedral interstitial site. A single hydrogen atom has the minimum embedding energy about -3.12 and -2.22 eV in the octahedral interstitial site of fcc δ-Pu at non-spin polarization and spin-polarization levels, respectively. The embedding energy in tetrahedral interstitial site is little larger than that in tetrahedral interstitial site. Hydrogen atom in δ-Pu crystal most preferably diffuses along the path linked with different interstitials. The diffusion barrier along the path from octahedral interstitial site to tetrahedral interstitial site is 1.06 eV. The diffusion barrier along the reverse path is 0.38 eV. In addition, the diffusion barrier along the path from tetrahedral interstitial site to tetrahedral interstitial site is 1.83 eV, and the path from octahedral interstitial site to octahedral interstitial site corresponds to the highest diffusion barrier.

Key words: H atom, δ-Pu metal, Diffusion behavior, DFT, Periodical model

MSC2000: 

  • O641