Magnetic Anomalies of Self-Diffusion and Co Heterodiffusion in α-Fe

Abstract

The equations describing the temperature variation of D(T) in the entire region of the b.c.c.-Fe phases α and δ are given. These equations are used in analysing the magnetic Co-heterodiffusion anomaly in b.c.c.-Fe and, for comparison, in the re-analysis of α-Be self-diffusion data. The values obtained on the basis of the present analysis are, the pre-exponential factor D0p and the activation enthalpy Hp appropriate for a completely disordered state, the α-Fe exchange integral J0, the paramagnetic temperature Tp, and the ratio ΔHm/ΔHF of the excess activation enthalpies of vacancy migration ΔHM and formation ΔHF. The application of Zener's theory of D0 makes it possible to propose the pre-exponential factor D0f and the activation enthalpy Hf for a completely ordered ferromagnetic state. The relation of the magnetic diffusion anomaly to the α-Fe elastic constants is investigated.