Torsional impedance effect in Fe-rich amorphous wires

Abstract

An amorphous ferromagnetic wire with a highly positive saturation magnetostriction constant, made of Fe 73.5Si 13.5B 9Nb 3Cu 1, was simultaneously submitted to both, an AC current flowing through it and a torsional stress, in order to induce a helical magnetic anisotropy that modifies the magnetic domain structure and therefore the magnetic response of the sample. We study the torsion-impedance effect in an Fe-rich amorphous wire when it is submitted to different applied torsional stresses in both senses, up to 0.8 π rad/cm, as a function of the drive current frequency, in the range of 10 Hz–2 MHz. The experimental results are explained on the basis of the core-shell magnetic structure model combined with the skin effect.