Surface Magnetization Processes in Amorphous Microwires

Surface magnetization processes in ferromagnetic glass-coated amorphous microwires with positive, negative, and nearly zero magnetostriction have been investigated. The results indicate helical magnetization in the surface region of positive magnetostrictive microwires and enhanced soft magnetic properties on the axial direction. The typical bistable behavior of such microwires is maintained within the surface region. Nearly zero magnetostrictive microwires with diameters larger than 20 ¿m also display bistability in the surface region, whilst negative magnetostrictive ones are not bistable. The values of the metallic nucleus diameter and glass coating thickness affect the surface magnetoelastic anisotropy, as emphasized by the changes in the values of the axial and transverse switching fields. The obtained results are important for a better understanding and control over the surface magnetization processes for high frequency applications of amorphous microwires.