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

Abstract

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 × 10⁻⁶ eV/Å and 2.79 × 10⁻⁶ μ for the edge dislocation, and 1.62 × 10⁻⁴ eV/Å and 2.02 × 10⁻⁴ μ for the screw dislocation.

Acknowledgement

The work described in this paper was partially supported by a grant from the Research Grants Council of the Hong Kong Special Administration Region, P.R. China (Project no. HKU7201/03E).