Partitioning behavior of Al in a nanocrystalline FeZrBAl soft magnetic alloy

Atom probe field ion microscopy was employed to investigate the distributio n of Al in a nanocrystalline Fe88Zr7B3Al2 soft magnet with optimal magnetic performance. The atom probe concentration depth profiles show that the Al atoms preferentially partition into the residual amorphous phase, and the p artitioning factor of Al is approximately five times larger in the amorphou s phase than in the bcc Fe phase. Based on the experimental results, the be neficial effect of the addition of Al on the soft magnetic properties is at tributed to the change of the inherent magnetostriction constant of the res idual amorphous phase induced by Al partitioning. (C) 2000 American Institu te of Physics. [S0021-8979(00)00501-6].