Fluxgate effect in twisted magnetic wire

Abstract In this paper a novel kind of fluxgate is presented. The sensor is based on helical anisotropy of the ferromagnetic layer, electrodeposited on copper wire. The saturating field is provided by current flowing in the wire, and the output voltage is measured directly at the terminations of the wire. Therefore no coils are necessary, making possible high miniaturization of the sensor. The effect has been tested twisting the wire: the second harmonic is shown to be strongly dependent on the applied torsion. Consideration on the practical use of the sensors is finally presented.