Use was made of a number of simple models for diffusion in B2, L12 and D03 model structures in order to determine the percolation thresholds of the antistructural bridge mechanism. The tracer correlation factor, which was calculated in an adaptation to the ordered alloy of the Manning random alloy formalism, was used to determine the percolation thresholds. Monte Carlo computer simulation was used to provide an exact reference. It was shown that, in the B2 structure, the antistructural bridge mechanism required substantial levels of disorder in order to operate. In the L12 and D03 structures, it was possible for the antistructural bridge mechanism to initiate at a certain composition and low level of disorder, only to disappear at higher levels of disorder. In the L12 structure, a mechanism was found which closely coupled the diffusion of both components.

Kinetic Theory and Simulation of the Antistructural Bridge Mechanism in Ordered Alloys/Intermetallic Compounds of the B2, L12 and D03 Structure. I.V.Belova, G.E.Murch: Metal Physics and Advanced Technologies, 2001, 19[1], 55-62