Magnetic Properties of FeCoNbB Nanocrystalline Alloys Heat treated under longitudinal magnetic field

Abstract

The formation of a nanocrystalline structure and its influence on the magnetic properties was investigated in the melt-spun Fe₈₁Nb₇B₁₂ and (FeCo)₈₁Nb₇B₁₂ alloys. Special attention has been focused on the study of the response of these alloys to the heat treatment under an applied magnetic field. We have shown that in the (FeCo)₈₁Nb₇B₁₂ alloy, which contains Fe and Co magnetic atoms in equal concentration, the heat treatment under longitudinal magnetic field of 20 kAm⁻¹ is accompanied by a marked improvement of the soft magnetic properties. On the other hand, the field-annealing effect in the Co-free alloy is negligible. This observation suggests that the phenomenon of field-annealing induced anisotropy in these alloys can be explained in terms of magnetic atom pairs ordering mechanism.