Magneto-impedance and ferro-magnetic resonance effects in thin amorphous wires and their application in functional composites materials at microwaves

The effect of the external magnetic field on microwave response from composites containing CoFeSiBCr amorphous wires has been demonstrated by measuring S-parameters in free space in the frequency band of 0.9-17 GHz. Two types of composites made of lattices of continuous and short -cut wires are considered to employ different types of spectra of the dielectric function (plasmonic and resonant). In both cases, the application of the field increases the dielectric losses owing to increase in the wire impedance. The observed changes in the reflection/transmission spectra are more than 10% in a certain lower frequency range. The results are analyzed in terms of the effective permittivity.