钼中空位在杂质氮捕获中的作用

The role of vacancy on trapping impurity of nitrogen in molybdenum

摘要:

应用第一原理结合统计模型的方法，我们研究了钼中杂质氮与空位的相互作用。单个氮原子易于占据八面体间隙位。杂质氮很容易为空位所捕获，其捕获能为2.71 eV，与实验值一致。我们计算了与氮有关的点缺陷浓度，结果表明以N1V复合物形式存在的空位浓度明显增加。结果表明钼中空位在杂质氮的捕获中起到了关键的作用。

Abstract:

Employing the first-principles simulation combined with the statistical model, we have investigated the interplay between impurity of nitrogen (N) and vacancy in molybdenum (Mo). Single N atom is energetically favorable occupying the octahedral interstitial site. N atom can be found to easily bond at vacancy, and the trapping energy of N trapped by vacancy is 2.71 eV, in good agreement with the experimental result. Further, we predict vacancy concentration in the form of N1V complex in Mo, which notablely increases due to the presence of N, despite the concentration of interstitial N is still higher than that of N1V complexes. The results demonstrate the key role of vacancy on N trapping in Mo.