Domain structure and magnetization process of bent Fe-rich amorphous wires

Abstract

The magnetization process of highly magnetostrictive Fe-rich amorphous wires is reported here for toroidal configuration with low enough radii of curvature so that, the occurrence of a single and well defined Barkhausen jump for a certain value of the reverse applied field is observed. This bent configuration introduces a distribution of tensile and compressive axial stresses causing an eccentric inner core with respect to the wire axis, where the magnetization is axially oriented. In this work, the domain structure and the magnetization process for a bent Fe-base amorphous wire are mainly analyzed by means of magneto-optical Kerr effect in polished bent wires. A simplified model is developed considering the energy barrier that reverse nucleated domain must overcome during the magnetization reversal process. The evolution of the corresponding switching field with the radius of bending fits with the observed experimental behaviour.