Study of the mechanical behavior of BCC transition metals using bond-order potentials
M. Mrovec, V. Vitek, D. Nguyen-Manh, D. G. Pettifor, L. G. Wang, M. Sob.
Multiscale Phenomena in Materials. Experiments and Modeling, 578, 199-204, (1999)
Deformation properties of body-centered-cubic transition metals are controlled by the core structure of screw dislocations and their studies involve extensive computer simulations. In this paper we present the recently constructed bond-order potentials (BOP) that are based on the realspace parametrized tight-binding method. In order to examine the applicability of the potentials we have evaluated the energy differences of alternative structures, investigated several transformation paths leading to large distortions and calculated phonon dispersions. Using these potentials we have calculated γ-surfaces that relate to the dislocation core structures and discuss then the importance of directional bonding in studies of dislocations in transition metals.