A new method for determining the diffusion coefficient of vacancy-solute complexes, by measuring the critical time for the non-equilibrium grain-boundary segregation of solute atoms, was established. In samples which were cooled sufficiently quickly from a high temperature, and then held isothermally, the critical time was defined to be the holding-time at the lower temperature which was required for the level of segregation to reach a maximum value. By using this method, the Arrhenius parameters for the diffusion of vacancy-B complexes in the present B-doped alloy were deduced to be 10-5m2/s and 0.94eV. The numerical factor, , was found to be equal to 0.48, for the diffusion of vacancy-B complexes in this alloy.

T.Xu, S.Song, H.Shi, Z.Yuan, W.Gust: Materials Science Forum, 1992, 94-96, 519-24