Highly Sensitive DC Magnetic Field Sensor Based on Nonlinear ME Effect

Abstract

Under a high ac excitation field, the output voltage of magnetoelectric (ME) composite at the third harmonic is linearly proportional to dc magnetic field, which makes it an excellent dc magnetometer. We fabricated a PZT and metallic glass (MG) composite with a multi-pushpull mode configuration, which has large values of linear ME coefficient. We systematically investigated the nonlinear ME effect of the PZTMG composite at its electricmechanical resonance frequency of 30 kHz. The sensitivity to dc magnetic field is studied under different ac excitation field and dc bias field. We found that the highest sensitivity is 17.6VOe at zero bias field. The nonlinear ME magnetic sensor has been demonstrated with a limit of detection of 2 × 10-5 Oe to dc magnetic field.