Effect of DC curing magnetic field on the magnetoelectric performance of Metglas/PZT bilayer composites

In this work, we modulate the performance of magnetoelectric (ME) composites by introducing residual stresses during their preparation. During the bonding and curing of magnetostrictive and piezoelectric materials, we stretch the magnetostrictive materials by applying a constant DC magnetic field. When curing is complete, the withdrawal of the DC magnetic field causes the magnetostrictive material to shrink and introduces residual stresses in the ME composite. This causes the ME composite to form a small curvature in the lengthwise direction, which alters the efficiency of stress–strain transfer. The magnitude of residual stress can be tuned by applying different DC magnetic fields to optimize the performance of ME composites. The effectiveness of this preparation method can also be verified by finite element analysis. The experimental results show that the ME coupling coefficient of the ME composite with a bending vibration mode is increased from 275 to 481 V/cm/Oe by the optimization of the residual stress regulation, while the limit of detection remains at a good state. This work could provide an effective method for performance enhancement of low-frequency ME sensors and promote the practical application of ME sensors.