A first-principles study was made, of diffusion in B2-NiAl, that simultaneously accounted for all relevant hop mechanisms in kinetic Monte Carlo simulations. Diffusion in B2-NiAl occurs not only through first- and second-nearest-neighbour hops, but also through simultaneous pair-atom hops with the dominant transport mechanism being very sensitive to the bulk alloy concentration and degree of local disorder.

Atomic Transport in Ordered Compounds Mediated by Local Disorder - Diffusion in B2-NixAl1-x Q.Xu, A.Van der Ven: Physical Review B, 2010, 81[6], 064303