Nonlinear magnetization reversal of Co-based amorphous microwires induced by an ac current

Abstract

The magnetization reversal of ferromagnetic Co-based amorphous microwires carrying ac current is studied. The frequency spectra of the voltage Vφ induced in the pick-up coil wound around the microwires were analysed and were found to depend on the ac current amplitude I0 and external longitudinal dc magnetic field He. The even harmonics are shown to dominate in the frequency spectra of Vφ if the ac current amplitude exceeds some threshold value, which strongly depends on He. A high sensitivity of the even harmonic amplitudes to the longitudinal dc field is demonstrated. The experimental data are described in terms of the Faraday law and the quasi-static Stoner-Wohlfarth model. The results obtained may be of importance for the design of weak magnetic field sensors.