Anisotropic Dependence of Giant Magneto-Impedance of Amorphous Ferromagnetic Ribbon on Biasing Field

TL;DR

This study investigates how the giant magneto-impedance of amorphous ferromagnetic ribbons varies with different biasing field orientations, revealing anisotropic effects linked to magnetization response and permeability changes.

Contribution

It provides new insights into the anisotropic dependence of magneto-impedance on biasing field direction in amorphous ferromagnetic ribbons.

Findings

Impedance drops significantly with applied d.c. magnetic field.

Different field orientations require different biasing strengths to saturate impedance.

Impedance variation is due to changes in a.c. permeability related to magnetization anisotropy.

Abstract

The magneto-impedance (MI) in amorphous ribbon of nominal composition Fe73.5Nb3Cu1Si13.5B9 has been measured at 1MHz and at room temperature for different configurations of exciting a.c and biasing d.c. fields. A large drop in both resistance and reactance is observed as a function of d.c magnetic field. When the d.c and a.c fields are parallel but normal to the axis of ribbon, smaller magnetic field is needed to reduce the impedance to its small saturated value compared to the situation when fields are along the axis of ribbon. Larger d.c. field is required to lower the impedance when the d.c field acts perpendicular to the plane of the ribbon. Such anisotropy in magneto-impedance is related to the anisotropic response of the magnetization of ribbon. The large change of impedance is attributed to large variation of a.c permeability on the direction and magnitude of the dc biasing field.