α-Fe氦缺陷及弹性模量的第一性原理研究  

First-principles study of helium defect effects on the structure and elastic modulus of α-Fe

作　　者：汤新政 彭蕾[1] 时靖谊[1] 白永安[1] 

机构地区：[1]中国科学技术大学核科学技术学院,合肥230027

出　　处：《原子与分子物理学报》2016年第5期946-950,共5页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11375173)

摘　　要：基于密度泛函理论,针对聚变堆结构钢中子辐照后氦效应进行第一性原理模拟研究.通过计算α-Fe中He缺陷形成能,来分析不同类型He缺陷相对稳定性及磁性的影响,并针对相对稳定的替位He缺陷,计算氦缺陷对α-Fe弹性模量的影响.结果表明:磁性对替位氦缺陷影响较小,结合态密度数据可知,替位氦可能引起晶格常数增大和体模量降低,且氦相对浓度减小可能会引起对弹性模量降低影响的弱化.First principle modeling of helium effect was performed based on density functional theory.Formation energies of helium substitutional site defect（ SS）,tetrahedral interstitial site defect（ TIS）,octahedral interstitial site defect（ OIS） and vacancy site defect（ VS） in α-Fe were calculated and the magnetic effects were also investigated.The results showed that SS is the most stable and OIS is the most unstable.The magnetic effects on SS defect structure are not significant.For the SS defect structure,the lattice constants and elastic modulus were calculated to investigate helium defect effects.The results showed that lattice constants increase and bulk modulus decrease due to the helium defect.And the helium defect effects would become weaker with its concentration decreasing.

关 键 词：Α-FE 氦缺陷 形成能 弹性模量 第一性原理 

分 类 号：O483[理学—固体物理]