点缺陷对B2-CoSc化合物物性影响的第一性原理研究

发布时间：2018-05-16 10:21

本文选题：B-CoSc金属间化合物 + 第一性原理　；参考：《中国有色金属学报》2017年08期

【摘要】：利用第一性原理的Castep软件,对B2型金属间化合物Co Sc的16种点缺陷的热力学参数、电子结构和弹性常数进行计算,分析16种点缺陷存在的类型及对化合物力学性能的影响。结果表明:Co单空位形成热和结合能分别是-6.78 e V和-0.43 e V,Co单空位化合物最容易形成、稳定性最好;其次是Co单反位化合物,形成热和结合能分别是-6.152 e V和2.504 e V。从而得出16种点缺陷最稳定存在形式是Co空位和Co反位;存在的组态是Co单空位、Co双空位、Co三空位和Co双反位。由电子态密度图中的费米能级和赝能隙也定性判断出,Co空位和反位缺陷化合物比Sc空位和反位缺陷化合物稳定。计算6种点缺陷的泊松比?可知,Co三空位的化合物金属键最强、塑性最好。与完整的Co Sc金属间化合物塑性相比,有空位缺陷的金属间化合物塑性得到提高。
[Abstract]:The thermodynamic parameters, electronic structure and elastic constants of 16 point defects of B2 type intermetallic compound Co SC were calculated by first-principle Castep software. The existing types of 16 point defects and their effects on the mechanical properties of the compounds were analyzed. The results show that the formation heat and binding energy of the single vacancy are -6.78e V and -0.43 EV, respectively, and the stability is the best, and the formation heat and binding energy are -6.152e V and 2.504 EV, respectively, and the formation heat and binding energy are -6.152e V and 2.504 EV, respectively. Thus, it is concluded that the most stable forms of 16 point defects are Co vacancies and Co antipositions, and the configuration of these defects is Co single vacancy Co double vacancies and Co double inversion positions. The Fermi energy levels and pseudo-energy gaps in the electron density diagram also show that the Co vacancy and antipotential defect compounds are more stable than SC vacancy and antipotential defect compounds. To calculate the Poisson's ratio of six point defects? It can be seen that the metal bond of the compound is the strongest and the plasticity is the best. Compared with the intact Co SC intermetallic compounds, the plasticity of the intermetallic compounds with vacancy defects is improved.
【作者单位】：河南理工大学材料科学与工程学院;
【基金】：国家自然科学基金资助项目(51271073,51301063)~~
【分类号】：TG111.2

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