High current sensitivity and large magnetoelectric effect in magnetostrictive-piezoelectric concentric ring

Abstract

A magnetostrictive-piezoelectric concentric ring (MPCR) is fabricated, and its current sensitivity and magnetoelectric effect are studied theoretically and experimentally. The MPCR has an inner Tb0.3Dy0.7Fe 1.92/NdFeB/epoxy magnetostrictive composite ring with a circumferential magnetization and an internal magnetic biasing bonded concentrically to an outer Pb(Zr, Ti)O3 piezoelectric ceramic ring with a wall-thickness polarization. The current sensing in the MPCR is based on the direct coupling of vortex magnetic fields generated by current-carrying cables with the magnetoelectric effect in the MPCR structure. The MPCR shows high and linear current sensitivities and magnetoelectric voltage coefficients of 15-17 mV/A and 22-26 mV/Oe in the nonresonance frequency range of 1 Hz-50 kHz, and of 185 mV/A and 277 mV/Oe at the fundamental shape resonance of 96 kHz, for current and vortex magnetic field levels of up to 10 A and 6.7 Oe, respectively.