The effect of the magnetic ordering upon the diffusion of Nb in α-Fe was investigated. Measurements were made at 673 to 1073K using secondary ion mass spectrometry as an analytical tool. By expanding the temperature range with respect to the previous work, the Arrhenius plot revealed the variation of the slope at the Curie temperature and a soft-upward curvature in the ferromagnetic region. The curvature observed was fitted well by the model of Ruch et al. The parameter that took into account the influence of the magnetic order in the vacancy formation and mobility during the Nb diffusion process was quite similar to that observed in other non-magnetic diffusers. A possible explanation for such an effect was given; supported by ab initio calculations.

Nb Diffusion in Ferromagnetic α-Fe. R.A.Pérez: Applied Physics A, 2008, 92[2], 325-8