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稀土La在$lt;em$gt;α$lt;/em$gt;-Fe中占位倾向及对晶界影响的第一性原理研究
引用本文:王海燕,高雪云,任慧平,张红伟,谭会杰.稀土La在$lt;em$gt;α$lt;/em$gt;-Fe中占位倾向及对晶界影响的第一性原理研究[J].物理学报,2014,63(14):148101-148101.
作者姓名:王海燕  高雪云  任慧平  张红伟  谭会杰
作者单位:1. 内蒙古科技大学材料与冶金学院, 包头 014010; 2. 内蒙古白云鄂博矿多金属资源综合利用重点实验室, 包头 014010; 3. 中冶东方工程技术有限公司长材事业部, 包头 014010
摘    要:本文采用重合位置点阵理论构建了 α-Fe的Σ3110](112)对称倾转晶界模型,通过基于密度泛函理论的平面波超软赝势方法研究了稀土La元素在 α-Fe中的占位倾向. 结果表明,La在 α-Fe晶界的杂质形成能最低,因而La原子倾向于占据晶界区;掺杂La前后的 α-Fe晶界电子结构计算结果显示,La占位于 α-Fe晶界会使体系中的电荷发生重新分配,将提供更多电子用于晶界区成键,使得Fe原子得到更多的电子,这将导致掺杂区原子间结合有离子化趋势,从而使La与晶界区相邻Fe原子之间的相互作用加强,也使晶界原子与晶界两侧Fe原子的键合加强,从能量角度解释了材料宏观力学性能变化的原因;计算同时发现,La加入后,也使晶界上的原子成键区态密度左移,降低了体系的总能量,使晶界结构更为稳定. 关键词: La α-Fe')" href="#">α-Fe 晶界 第一性原理

关 键 词:La  α-Fe  晶界  第一性原理
收稿时间:2014-01-16

First-principles characterization of lanthanum occupying tendency in α-Fe and effect on grain boundaries
Wang Hai-Yan,Gao Xue-Yun,Ren Hui-Ping,Zhang Hong-Wei,Tan Hui-Jie.First-principles characterization of lanthanum occupying tendency in α-Fe and effect on grain boundaries[J].Acta Physica Sinica,2014,63(14):148101-148101.
Authors:Wang Hai-Yan  Gao Xue-Yun  Ren Hui-Ping  Zhang Hong-Wei  Tan Hui-Jie
Abstract:The α -Fe Σ3110] (112) symmetrical tilt grain boundary model is established by the coincidence site lattice theory. First-principles plane wave ultrasoft pseudopotential method based on the density functional theory is used to calculate the La occupying tendency in α -Fe. The results show that La elements tend to be located at grain boundary in the α -Fe since the impurity formation energy keeps lowest. On this basis, the electronic structure of La doped in α -Fe grain boundary is also calculated. The results indicate that the charges in the system are redistributed to provide more electrons for the grain boundary bonding when the La occupies α -Fe grain boundary. Meanwhile, Fe atoms obtain more electrons, and the La doped region combination has the ion-tendency toward strengthening the interaction between La atom and Fe atoms in the adjacent boundary region, and the Fe atom bonds in the grain boundaries and on both sides of the grain boundary also strengthen, which is the reason why the mechanical properties change from the energy point of view. Moreover, La addition also makes the atomic density of states on the grain boundary move to the left, reduce the total energy of the system, and make the grain boundary more stable.
Keywords: La α-Fe')" href="#">α-Fe grain boundaries first-principles
Keywords:La  α-Fe  grain boundaries  first-principles
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