arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1302.3002cond-mat.mtrl-sci
收藏

氢、氘和氚在$α$ -Ti中扩散系数随温度变化的第一性原理研究

First-principles study of temperature-dependent diffusion coefficients: Hydrogen, deuterium, and tritium in $α$-Ti

Yong Lu, Ping Zhang

摘要:

我们报道了用过渡态理论预测间隙氢、氘和氚原子在$α$ -Ti中随温度变化的扩散系数。杂质扩散系数的前因子和激活能中的微观参数由第一性原理总能量和声子计算得到,包括扩散原子与基质晶格的振动模式之间的完全耦合。考虑了杂质原子在hcp矩阵中的双重占据情况,并将四条扩散路径合并得到最终的扩散系数。计算的扩散参数与实验结果吻合较好。数值计算结果表明,在425 K和390 K以上,氘和氚原子的扩散比氢原子的扩散慢。

英文摘要:

We report the prediction of temperature-dependent diffusion coefficients of interstitial hydrogen, deuterium, and tritium atoms in $α$-Ti using transition state theory. The microscopic parameters in the pre-factor and activation energy of the impurity diffusion coefficients are obtained from first-principles total energy and phonon calculations including the full coupling between the vibrational modes of the diffusing atom with the host lattice. The dual occupancy case of impurity atom in the hcp matrix are considered, and four diffusion paths are combined to obtain the final diffusion coefficients. The calculated diffusion parameters show good agreement with experiments. Our numerical results indicate that the diffusions of deuterium and tritium atoms are slower than that of the hydrogen atom at temperatures above 425 K and 390 K, respectively.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑