Atomic simulation of the dynamic properties for a double period structure with 90° partial dislocation in Si

The dynamic properties of a double period (DP) structure with a 90° partial dislocation were investigated by atomic simulation methods in Si. By the use of molecular dynamics (MD) method, the motion sequences of kinks and reconstruction defect (RD) of DP structure were obtained. Based on the conjugate gradients (CG) results and tight-binding (TB) potential, the formation energies E_f of kinks were computed. In addition, the migration barriers W_m of kinks were also calculated via nudged elastic band (NEB) method with TB potential. The results show that E_f is smaller than W_m, which means that the migration barrier of kink dominates the motion of DP structure. According to the activation energies of short dislocation segments (2.17 eV) and long dislocation segments (1.61 eV), we predict that the experimental results may be between these two values.