Magnetic flux modulation with electric controlled permeability for magnetoresistive sensor

Owing to the attractive advantages of the simple preparation process, convenient frequency adjustment, and stable mechanical structure, magnetic flux modulation with electric controlled permeability exhibits a better performance in the reduction of 1/f noise for magnetoresistive (MR) sensors than other schemes of magnetic flux modulation. However, the magnetic flux electric modulation (MFEM) has not been experimentally verified. In this work, a prototype of the MFEM structure was established by preparing an FeGaB film on a Pb(Mg1/3Nb2/3)0.7O3–PbTi0.3O3 substrate, and the modulation structure was integrated into an MR sensor. A test system was built to evaluate the modulation efficiency of the MFEM structure, and the results showed that the modulation efficiency reached 9.8% with an applied electric field of 2 kV/cm at a frequency of 10 010 Hz. Meanwhile, experiments were carried out to study the effects of driving electric fields’ amplitude and frequency on modulation efficiency, and it was revealed that the modulation efficiency could be further improved by increasing the amplitude of driving voltage and reducing the thickness of the ferroelectric layer.