Si中30°部分位错弯结-重构缺陷运动特性的分子模拟  

Molecular Simulation for Migration Characteristics of Kink-Reconstruction Defect Complex on 30° Partial Dislocation in Silicon

作　　者：孟庆元[1] 王庆盛[1,2] 

机构地区：[1]哈尔滨工业大学航天科学与力学系,哈尔滨150001 [2]北京强度环境研究所,北京100076

出　　处：《西安交通大学学报》2009年第5期124-127,132,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(10772062)

摘　　要：通过基于EDIP(Environment-Dependent Interatomic Potential)势函数的分子动力学模拟,得到了左弯结-重构缺陷(LC)和右弯结-重构缺陷(RC)在1个周期内通过稳定状态之间的相互转化来实现运动的具体过程,同时给出了LC和RC在不同温度和剪应力作用下的运动速度曲线.通过NEB(Nudged Elastic Band)方法结合紧束缚势函数,计算出了LC和RC在1个周期内的迁移势垒,验证了分子动力学结果的正确性.计算结果表明,含有重构缺陷(RD)的LC和RC相对于左弯结和右弯结具有较快的运动速度,验证了之前得出的RD对30°部分位错的运动具有加速作用的结论,并且通过对弯结运动过程中微观结构的分析,从微观尺度上对这一结论进行了解释.The migration processes of left kink-reconstruction defect complex （LC） and right kink-reconstruction defect complex （RC） in one period are obtained by using the molecular dynamics method based on the environment-dependent interatomic potential （EDIP）. The migrations proceed through the transformation among the steady states in the period. And the velocity characteristics of LC and RC are investigated under different temperature and shear stress conditions. The migration energies of LC and RC in one migration period are calculated by performing the nudged elastic band （NEB） calculations with the tight binding （TB） potential. These energy data coincide well with the dynamics results. It is known that LC and RC containing the reconstruction defect （RD） move faster than the left kink （LK） and right kink （RK）, which validates our previous conclusion that RD can promote the motion of the 30° partial dislocation. Moreover,this conclusion is explained at the atomic level by the observation of microstructures during the motion.

关 键 词：部分位错 分子动力学 弯结-重构缺陷 迁移势垒 

分 类 号：O411.3[理学—理论物理] O474[理学—物理]