Self-diffusion in iron

Abstract

Self-diffusion measurements in pure, polycrystalline iron have been carried out in the temperature ranges 860 to 900°c and 1150 to 1515°c. These include parts of the paramagnetic α phase (b.c.c.), and of the γ phase (f.c.c.), and the whole of the δ phase (b.c.c.). The isotope ⁵⁵Fe was used and diffusion zone analysis was carried out by autoradiography. The following expressions for diffusion coefficientsD, have been deduced from least squares analyses of the results: Within experimental error, the results for the two b.c.c. phases fit the single relation . They suggest that there is no appreciable diffusion effect of magnetic ordering extending well above the Curie temperature, of the kind recently suggested by Borg et al.