Penetration Depth and Magnetoimpedance Effect in CoFeSiB and FeNbCuSiB Amorphous Wires

The magnetoimpedance (MI) elements prepared on amorphous cobalt-based Co68.15Fe4.35Si12.5B15 and iron-based Fe73.5Nb3Cu1Si13.5B9 wires prepared by the melt-spinning technique were studied. In addition to the investigation of the MI-effect by MI-modulus Z (Hex, f), an analysis of penetration depth δm (Hex, f), which is a crucial MI-parameter, was performed by exploiting MI-element magnetoresistance MR (Hex, f). Comparative studies of the dependence of the skin depth on the magnetic field and frequency δm (Hex, f) have shown that the cobalt-based amorphous wires attain an order of magnitude lower penetration depth values.