Piezoelectric-metal-magnet dc magnetoelectric sensor with high dynamic response

Abstract

A dc magnetoelectric sensor capable of measuring both dc and ac magnetic fields is developed by combining a thickness-polarized 0.7Pb(Mg1/3Nb2/3)O3–0.3PbTiO3 (PMN–PT) piezoelectric single-crystal plate, a pair of electrically connected aluminum strips, and a pair of NdFeB magnet plates in orthogonal directions. The operation of the sensor is based on the mechanical mediation of the magnetically biased Lorentz force effect in the aluminum strips due to a drive magnetic field (B3D) applied to the sensor, a dc bias magnetic field (B3B) preset by the NdFeB plates, and an ac reference electric current (I2) flowing through the aluminum strips with the transverse piezoelectric effect in the PMN–PT plate at the sensor resonance. The theoretical and experimental results confirm an ultrahigh and linear current-controlled magnetic field sensitivity of 1.7 V/T/A in broad ranges of B3D amplitude of −100 to 100 mT and B3D frequency of 0–15 kHz by using an I2 of ≤100 mA at the sensor resonance frequency of 65 kHz.