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-2.22eV.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1.06eV,而四面体间隙到八面体间隙的扩散能垒为0.38eV.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1.83eV,八面体间隙到八面体间隙交替扩散路径的能垒最高,为2.52eV.
The diffusion behavior of hydrogen atom in 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.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2008年第11期1964-1968,共5页
Acta Physico-Chimica Sinica
