Magnetoelectric Transducer Employing Piezoelectric Ceramic/Ferromagnetic Alloy/High-Permeability FeCuNbSiB Composite

This feature of rather large magnetoelectric (ME) coupling at the resonance enables the ME composites to possess great ME energy conversion ability. This paper proposes a new type of ME transducer fabricated from the ferromagnetic alloy FeNi-FACE, high-permeability FeCuNbSiB (Fe_73.5Cu₁Nb₃Si_13.5B₉) and piezoelectric PZT-8H to achieve the strong ME coupling. On one hand, the effective mechanical quality factor (Q_m) of the transducer is significantly high because of the high quality factor values of FeNi-FACE, PZT-8H and FeCuNbSiB respectively. On the other hand, FeCuNbSiB acts as the dynamic driver to enhance the effective piezomagnetic coefficient d₃₃ of the FeNi-FACE. A high ME voltage coefficient (MEVC) and a high ME power output can be obtained since the MEVC and power output at resonance strongly depend on the d₃₃ and the Q_m. The experimental results show that the strain coefficient of the FeNi-FACE/FeCuNbSiB laminate at resonance achieves 250 nm/A under H_dc = 23 Oe, which is 6.02 times as high as that for a single FeNi-FACE layer. The maximum MEVC at resonance (α_r) achieves 4.65 V/Oe, which is 1.6 times larger than that of the previous Terfenol-D/PZT/Terfenol-D (MPM) composite transducer. The new transducer can obtain an output power of 103.7 μW under a resonant excitation H_ac = 0.4 Oe, which is ~16 times higher than that of the previous ultrasonic-horn-substrate composite transducer and decreases the size by nearly 75%.