Using modified analytical embedded-atom methods and molecular dynamics simulation, the strain energy and the equilibrium core structure of a<100> edge dislocation in body-centered cubic iron were simulated at the atomistic scale. In addition, the trapping effect of dislocation on vacancy was investigated as well. The results showed that the equilibrium dislocation core was quite narrow and had a C2v symmetry structure. Calculated strain energy Es of the dislocation was a linear function of ln(R/2b) while R ≥ 5.16Å, in excellent agreement with the elasticity theory prediction. Determined core radius and energy were 5.16Å and 0.62eV/Å, respectively. The closer the vacancy to the dislocation line is, the lower the vacancy formation energy is, this fact implies that the dislocation had a trend to trap the vacancy, especially for a separation distance of the vacancy from dislocation line being less than two lattice constants.

Relaxed Energy and Structure of Edge Dislocation in Iron. Y.Zhang, L.J.Xie, J.M.Zhang, K.W.Xu: Chinese Physics B, 2011, 20[2], 026102