Helical magnetic structure in cold-drawn Fe-rich amorphous wire

From the observations of the magnetoimpedance effect on Fe-rich amorphous wires, our work is devoted to the investigation of the magnetic structure of Fe_77.5B₁₅Si_7.5 amorphous wires obtained by in-rotating-water-quenching technique and reduced by cold-drawn process to 0.05 mm. The results of the magneto-optical Kerr effect and X-ray diffraction methods show that current annealing produces strong helical anisotropy in the cold-drawn Fe-rich wires. We consider that the formation of the helical anisotropy in the studied wires is related to the deformation, which was observed on the surface of the wire after the cold-drawing process, and could also be considered as the driving force for the crystallization.