Atomistic simulation of the 60 degrees dislocation mobility in silicon crystal

作者：Li Cheng xiang^*; Meng Qing yuan; Li Gen; Yang Li jun

来源：Superlattices and Microstructures, 2006, 40(2): 113-118.

DOI：10.1016/j.spmi.2006.05.004

• dislocation dipole
• dislocation velocity
• the Peierls stress
• molecular dynamics simulation

Dislocation velocity and mobility are studied via molecular dynamics simulation for a 60 dislocation dipole in silicon crystal. The atomic interactions are described using the Stillinger-Weber potential and the external stress is applied by means of the Parrinello-Rahman algorithm. It is found that the dislocation begins to move when the applied stress is larger than the Peierls stress, and the calculated Peierls stress decreases as the temperature increases, which is in agreement with the Peierls-Nabarro model. The dislocation velocity at relatively low temperature is insensitive to variation of temperature. In fact, the velocity increases monotonically as the stress increases, and eventually approaches its plateau velocity which is about 2900 m/s. At higher temperature, however, the velocity no longer increases monotonically as the stress increases and the plateau velocity decreases as the temperature increases. In general, the dislocation velocity decreases as the temperature increases, which is consistent with the phonon drag model.

• 出版日期2006-8
• 单位哈尔滨工业大学