密排六方金属中多空位的改进分析型嵌入原子法计算

应用改进分析型嵌入原子法(Modified Analytical Embedded-Atom Method,MAEAM),计算了密排六方(Hexagonal Closed-Packed,HCP)金属(c/a<1.633)单空位形成能以及双空位与三空位的形成能与结合能.空位形成能的最小值或结合能的最大值均表明,双空位稳定结构是第一近邻[1n]、第二近邻[2n]或第三近邻[3n];三空位稳定结构是三空位组成两个第一近邻和一个第二近邻[112]、一个第一近邻和一个第二近邻以及一个第三近邻[123]或三个第二近邻[222].这说明在密排六方金属(c/a<1.633)中存在空位聚集趋势.

Atomic simulation of the vacancies in HCP metals with the Modified Analytical Embedded-Atom Method (MAEAM)

The formation energy of the mono-vacancy and both the formation energy and binding energy of the di-vacancy and tri-vacancy in HCP metals are calculated by using the Modified Analytical Embedded-Atom Method(MAEAM).It is seen from the minimum of the formation energy or maximum of the binding energy,the favorable configuration of the di-vacancy is the first-nearest-neighbor ,the second-nearest-neighbor or the third-nearest-neighbor ,and that of the tri-vacancy is the constructed by two first-nearest-neighbor vacancies and one second-nearest-neighbor,the constructed by one first-nearest-neighbor and one second-nearest-neighbor and one third-nearest-neighbor or the constructed by three second-nearest-neighbors.It is indicated that there is a concentration tendency for vacancies in HCP metals.