Ferromagnetic resonance investigation of surface anisotropy distribution in amorphous glass-covered wires

The distribution of the magnetic anisotropy in the surface region of amorphous glass-covered wires with positive and nearly zero magnetostriction is analyzed by means of microwave absorption ferromagnetic resonance (FMR). The surface layer of as-cast positive magnetostrictive amorphous glass-covered wires displays an axial anisotropy, which changes to radial after partial or complete removal of the glass cover. The as-cast nearly zero magnetostrictive amorphous glass-covered wires display a circumferential anisotropy in their surface layer, its direction being maintained even after partial or complete glass removal, but its strength slightly increases with glass removal. The results are explained by taking into account the most recent results on the domain structure of these wires, as well as the skin effect that occurs at microwave frequencies.