Si中30度部分位错弯结运动特性的分子模拟
Molecular Simulation on Migration of Kinks on a 30° Partial Dislocation in Silicon
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摘要: 首先使用分子动力学方法(MD)得出了左弯结(LK)和右弯结(RK)在不同温度和剪应力作用下的速度特性和运动过程.然后利用基于紧束缚势(TB)的nudged elastic band(NEB)方法计算LK和RK的迁移势垒.由计算结果得出,单个LK或RK的势垒很高,运动速度相对较慢;LK中的多弯结对结构和由RK分解产生的右弯结-重构缺陷(RC)能够加速位错运动;其中,RC能促进30°部分位错更快地迁移.Abstract: Left kink (LK) and right kink (RK) migration and velocity at different temperatures and shear stresses are obtained with molecular dynamics (MD) method. By means of nudged elastic band method (NEB) based on tight binding (TB) potential, migration energies of LK and RK are calculated. It shows that due to high migration energy a single LK or RK moves slowly. Multiple kink pair structure of LK and RK-reconstruction defect (RC) dissociated from RK accelerate motion of LK and RK. Particularly, RC makes 30° partial dislocation move faster.
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