Full-scale atomistic simulations of dislocations in Ni crystal by embedded-atom method

摘要

Full-scale atomistic simulations by the nudged elastic band method are performed to determine the energetics and core structures of dislocations in a Ni lattice using an embedded-atom method potential. We. find that for an edge dislocation, the potential yields very weak coupling between the partials which move almost individually. For a screw dislocation, the coupling between the partials is somewhat stronger and the partials move with some dependence. As expected, the results indicate that stacking fault energy has a controlling influence on the coupling behaviour of the partials. The effective Peierls energies and stresses are 1.30 x 10(-6) eV/angstrom and 2.79 x 10(-6) m for the edge dislocation, and 1.62 x 10(-4) eV/angstrom and 2.02 x 10(-4) m for the screw dislocation.