Influence of distributed surface-normal magnetic field on the permeability of magnetostrictive Co-Nb-Zr thin-film strips

A clustered narrow-strip element, fabricated from an amorphous soft magnetic thin film with specific in-plane magnetic anisotropy, has been investigated for permeability control via the application of a magnetic field oriented normal to the substrate. The element initially exhibits low permeability due to the longitudinal single-domain state within each strip. Permeability was observed to increase sharply, contingent upon the spatial non-uniformity of the applied normal magnetic field. This non-uniformity is precisely defined by the ratio of the positional variation of the applied field's in-plane vector component (the "intensity of distribution"). To rigorously determine the impact of this phenomenon, this study investigates an amorphous Co-Nb-Zr alloy, chosen for its intrinsic magnetostrictive effect, to quantify its influence on the permeability control characteristics of the narrow-strip element.