FCC金属空位的MAEAM理论研究  

MAEAM research on vacancies for fcc metal

作　　者：陈学善[1,2] 赵越[1] 郭金明[1] 杜安[1] 

机构地区：[1]东北大学理学院,沈阳市110819 [2]金日成综合大学原子能系

出　　处：《原子与分子物理学报》2012年第4期717-724,共8页Journal of Atomic and Molecular Physics

基　　金：国家重点基础研究发展计划项目(2011CB606404)

摘　　要：应用涉及更远邻原子的改进分析型嵌入原子方法(MAEAM)计算了面心立方(fcc)金属(Ag,Al,Au,Cu,Ir,Ni,Pd,Pt,Rh)的空位性能.在MAEAM计算中,考虑了远邻原子相互作用和单空住迁移能,对两体势进行了坚挺处理,并采用新的截尾函数和加强光滑连接条件对两体势作了截尾处理.同时为了更好的符合面心立方晶体的结合能、弹性常数和平衡条件,调整了多体势的模型常数.未弛豫空住性能计算中考虑了两体势的截尾距离和电子密度分布函数的截尾距离之间近邻原子的作用以及双空位迁移途径周围的原子非对称分布.结果与其它方法计算结果基本一致,但更加接近实验值.对双空住迁移能的计算结果有利地说明了fcc金属双空住5种迁移途径的扩散机制.The vacancy properties of fcc metals （Ag, Al, Au, Cu, Ir, Ni, Pd, Pt and Rh） were calculated with farther neighbor MAEAM theory. The pair potentials were stiffened and a new truncated function and an enhanced smooth connection condition were applied to the cutoff procedure of pair potential by considering farther neighbor atoms and mono-vacancy migration energy. The parameters of multi-body potential were also adjusted to fit cohesive energy, elastic constants and an equilibrium condition of fcc crystal. The inter-action of the neighbor atoms between the truncated distances of pair-potential and electron density distribution function were contemplated and the asymmetric atom distribution around bi-vacancy migration paths was also discussed in the calculation of unrelaxed vacancy properties. The results are in agreement with those obtained by other calculations, and more close to the experimental data. The calculations of bi-vacancy diffusion demonstrate all possible jumps of bi-vacancy migration mechanism well.

关 键 词：多体势 空位性能 改进分析型嵌入原子方法 面心立方金属 

分 类 号：O56[理学—原子与分子物理]