摘要
利用基于密度泛函理论的第一性原理深入研究了复六方C36构型Laves相MgNi_2的力学性能和点缺陷,采用96个原子的超胞结构研究了10种存在的点缺陷结构,包括5种反位缺陷和5种空位缺陷。从缺陷形成能与化学势的函数图中可以发现,Mg原子反位Wyckoff4f位置的Ni原子时(MgNi_3)在富镁和富镍的条件下都具有最低的缺陷形成能,Mg1和Mg2在Wyckoff 4f和4e位置的空位缺陷在富镁和富镍的条件下都是最难以形成的。进一步讨论了MgNi_2缺陷形成的内部因素,反位缺陷MgNi_3具有最强烈的原子间相互作用,其最稳定且符合缺陷形成能的结论。
The mechanical properties and point defects of dihexagonal Laves phase C36 MgNi2 were studied by using the first principle based on the density functional theory, and 10 kinds of point defect structures, including 5 kinds of reverse defects and 5 vacancy defects, were studied by the supercellular structure of 96 atoms. From the function diagram of the formation energy and chemical potential of the defect, it’s found that the Ni atom of the Mg atom Wyckoff 4 f position(MgNi3) had the lowest defect formation energy under the magnesium-rich and nickel-rich conditions. It’s the most difficult to form the vacancy defects of Mg1 and Mg2 at the Wyckoff 4f and 4 E positions under the magnesium-rich and nickel-rich conditions. The internal factors of the formation of MgNi2 defects were further discussed. It’s pointed out that the antisite defect MgNi3 had the strongest interatomic interaction, and it’s most stable, which conformed to the conclusion of defect formation energy.
作者
王佳宁
李雅雯
WANG Jian-ning;LI Ya-wen(Guangxi University,Guangxi Nanning 530004,China)
出处
《当代化工》
CAS
2018年第12期2507-2509,2513,共4页
Contemporary Chemical Industry
基金
自然科学基金支持下
中国批准号51461002
关键词
点缺陷
缺陷形成能
电子结构
LAVES相
镁合金
Point defect
Defect formation energy
Electronic structure
Laves phase
Magnesium alloy
