Self-diffusion of BCC transition metals calculated with MAEAM

The energy during the process of self-diffusion in BCC transition metals Fe, W, Mo, Cr, Ta, Nb and V has been calculated by using modified analytic embedded-atom method (MAEAM). For each kind of three diffusion mechanisms nearest-neighbor (NN), nextnearest-neighbor (NNN) and third-nearest-neighbor (TNN), the energy curve is symmetric and the maximum value of the energy appears at the middle point of the diffusion path. Determined mono-vacancy formation energy E-1v(f), migration energy E-1v(m) and activation energy Q(1v) for self-diffusion agree well with available experimental data of NN diffusion and are better than those obtained by the analytic embedded-atom method (AEAM) and Finnis-Sinclair models. Compared the energies corresponding to three diffusion mechanisms, the NN diffusion needs the lowest activation energy (and thus the lowest migration energy). So that, the NN mono-vacancy diffusion is favorable in BCC transition metals. (c) 2006 Elsevier B.V. All rights reserved.