Magnetoimpedance Tomography of Amorphous CoFeTaSiB Wires

The results are presented for the study of the radial distribution of the magnetic permeability of an amorphous Co 66 Fe 4 Ta 2.5 Si 12.5 B 15 wire of 55 μm in radius performed using magnetoimpedance tomography within a range of alternating current frequencies from 0.01 to 100 MHz. It has been found that the value of magnetic permeability strongly depends on a radial coordinate. In this case, the inner regions of the wire are predominantly axially-anisotropic, while the outer layer about 2.5 µm thick is circularly-anisotropic. It has been shown that the magnetoelastic mechanism is not the main one in the formation of magnetic anisotropy in the surface layer of a wire.