Evaluation of diffusion data in the type AB transition regime

In the literature, characterization of new diffusion regimes can be found that can better describe measured diffusion profiles in fine-grained advanced materials. In this connection, the possibility to evaluate the measured data also in the transition-type kinetics gathers importance. Recently, some diffusion experiments were published introducing nanostructured materials in the transition regime between the Harrison's types A and B. In this regime (called type AB kinetics), the penetration profiles correspond to the relation lnc¯∼yn. Here, the exponent n varies from 2 to 6/5 as the diffusion regime changes from types A to B. This paper presents an easy approximate method for estimation of the grain boundary (GB) diffusion characteristics from sectioning measurements in the type AB transition kinetics.