Influence of strong static magnetic field on intermediate phase growth in Mg–Al diffusion couple

Effects of strong magnetic field on intermediate phase growth in Mg–Al diffusion couples is addressed. It was found that both Al3Mg2 (β) and Al12Mg17 (γ) formed after annealing at different temperatures with or without the field. Systematic measurements showed that thickness of intermediate phases was reduced due to the application of the 10 T static magnetic field. Data analysis show that reduction of intermediate layer thickness is attributed to the decreasing of frequency factor (k0) under the magnetic field, however the activation energy (Q) for layer growth is almost not changed irrespective of the application of the field. Layer thickness decreasing is suggested to be related with the retardation of atom diffusion resulting from the magnetic field and a possible theory based on ambipolar diffusion is discussed to explain this effect.