The effect of domain-walls motion on second harmonic amplitude of magnetoinductive response in Co-based amorphous wires

The influence of domain-walls motion on the magnetoinductive response of Co-based amorphous wires having helical anisotropy has been studied. A model describing the domain-walls motion in the field of AC current in the absence of the skin effect is proposed. It is shown that at high enough AC current amplitudes, the domain-walls motion results in the appearance of the second harmonic in the magnetoinductive response. The second harmonic amplitude is studied as a function of the longitudinal external magnetic field, the current frequency and the angle of the deviation of the anisotropy axis from the circular direction for both the voltage across the wire and the pick-up coil voltage. It is demonstrated that the field sensitivity of the second harmonic can be significantly higher than that of the first harmonic.