Voltage-mode direct-current magnetoelectric sensor based on piezoelectric–magnetostrictive heterostructure

A dc magnetoelectric sensor operating in ac voltage driving mode is developed based on a piezoelectric–magnetostrictive heterostructure having four thickness-polarized Pb(Zr, Ti)O3 piezoelectric plates bonded symmetrically on a length-magnetized Tb0.3Dy0.7Fe1.92 magnetostrictive plate to give an electrically parallel input and an electrically series output. The dc magnetic field sensing in the sensor is evaluated theoretically and experimentally and is found to originate from a unique ac voltage-driven, dc magnetic field-tuned resonance dc magnetoelectric effect in the heterostructure. An interestingly high, linear, and negative ac voltage-controlled dc magnetic field sensitivity of −1.3 mV/Oe/V is obtained in a broad range of dc magnetic field of 0–400 Oe by referencing an ac voltage of ≤5 V peak amplitude and 116 kHz frequency at the input of the heterostructure.