氧在钒中基本热力学行为的第一性原理研究

发布时间：2018-05-23 06:35

本文选题：钒 + 杂质氧　；参考：《北京航空航天大学学报》2017年05期

【摘要】：钒(V)是核聚变反应堆结构材料的重要候选材料。实验表明杂质氧(O)会对V的结构和力学性能产生极大的影响。采用基于密度泛函理论的第一性原理方法研究了O在V中热力学稳定性、扩散特性以及与缺陷空位的相互作用。O在V中易于占据八面体间隙位,其溶解能为-4.942 eV。O在间隙位的最佳扩散路径为八面体间隙位→四面体间隙位→八面体间隙位,扩散激活能为1.728 eV,在此基础上对不同温度下的扩散系数在文中给出了详细分析。O在V中与空位存在很强的吸引相互作用,1个O原子和2个O原子被空位捕获时的捕获能分别为-0.484 eV和-0.510 eV。当O原子的数量超过3,其捕获能变为正值0.382 eV,因此单空位最多能够结合2个O原子,这意味着"O_1-vacancy"和"O_2-vacancy"团簇在V中很容易形成。这些研究结果将对V基合金在核聚变反应堆中的最终应用具有一定的参考价值。
[Abstract]:Vanadium V) is an important candidate material for nuclear fusion reactor structural materials. The experimental results show that the impurity O (O) has a great influence on the structure and mechanical properties of V. The first principle method based on density functional theory is used to study the thermodynamic stability of O in V, the diffusion characteristics and the interaction with defect vacancies. The optimum diffusion path of its dissolution energy is -4.942 eV.O in the gap position. The octahedron gap position is the tetrahedron gap position and the octahedral gap position. The diffusion activation energy is 1.728 EV. On the basis of this, the diffusion coefficient at different temperatures is analyzed in detail in this paper. There is a strong attractive interaction between .O and vacancies in V, and one O atom and two O atoms are trapped by vacancy. The capture energy is -0.484 EV and -0.510 EV, respectively. When the number of O atoms exceeds 3, the trapping energy becomes positive 0.382 EV, so a single vacancy can bind at most 2 O atoms, which means that "O_1-vacancy" and "O_2-vacancy" clusters are easily formed in V. These results will have some reference value for the final application of V-base alloy in nuclear fusion reactor.
【作者单位】：中国科学院电工研究所;烟台大学光电信息科学技术学院;
【基金】：国家自然科学基金(11575153)~~
【分类号】：O414.1;TL627

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