Resonant behavior of Sn diffusion coefficient in α-Fe in pulsed magnetic field at 730-750 °С

The effect of the constant and pulsed magnetic fields (PMF) impact on processes of the atom transport within a crystal lattice can serve an instrument for studying of diffusion mechanisms and relaxation processes in ferromagnetic metals and alloys [1]. The present experimental research was aimed to study the PMF influence on the Sn diffusion coefficient (DC) in α-Fe within the magnetic field intensity range of 39.8–557.2 kА/m and frequency range of 1–21 Hz at 730-750 °С.

The measuring of DC was performed by X-ray diffraction analysis. The magneto-diffusive effect (MDE), i.e. the effect of appreciable PMF influence on the measured DC for Sn in α-Fe is revealed and established by the authors. In particular, the resonant behavior of Sn DC for frequencies of 5 and 13 Hz was found out within the measured frequency spectrum. The investigated resonant behavior of DC for Sn in α-Fe is explained by magnetostriction of ferromagnetic α-Fe in external PMF. The interaction between elastic field of defect complexes (couple of impurity atoms and couple of impurity atom–vacancy) and elastic stress fields of α-Fe crystal lattice has an influence on mass transfer. The main cause for this interaction is magnetostrictive stresses in α-Fe under of external PMF. Also, possible mechanisms of the MDE such as Zener’s relaxation and elastic interaction of dislocations with α-Fe moving domain walls [2] are considered.

[1] Pokoev А.V., Fedotov A.A. Magneto-diffusional effect in ferromagnets in the constant and pulsed magnetic fields. Defect and Diffusion Forum 363 (2015) 190.

[2] Pokoev А.V., Verjakovskaya М.A. Influence of pulsed magnetic field on Al-heterodiffusion in α-Fe. Defect and Diffusion Forum 289-292 (2009) 323.