Molecular dynamics simulations of the diffusion process in ordered B2 NiAl at high temperatures were performed by using an embedded atom interatomic potential. Diffusion occurred via various cyclic mechanisms that accomplish the motion of the vacancy through nearest-neighbor jumps restoring order to the alloy at the end of the cycle. The traditionally postulated six-jump cycle was only one of the various cycles observed and some of these were quite complex. A detailed sequential analysis of the observed 6-jump cycles was performed and the results were analyzed in terms of the activation energies for individual jumps calculated using molecular statics simulations.

Molecular Dynamics Simulations of Diffusion Mechanisms in NiAl. B.S.De Bas, D.Farkas: Acta Materialia, 2003, 51[5], 1437-46