Geometry-Controlled Magnetoelectric Response in Metglas/PZT Laminate Composites With Microstructured Ferromagnetic Layers

Microstructured magnetoelectric (ME) laminate composites are attractive for low-field magnetic sensing because their performance can be tuned through geometric control of the ferromagnetic (FM) phase. In this work, Metglas/PZT ME sensors with patterned FM layers were fabricated by a combined laser-cutting and wet-etching process and studied to clarify the influence of microstructural geometry on magnetic behavior and ME response. Vibrating sample magnetometry (VSM) showed that all samples retained the soft-magnetic character of amorphous Metglas with coercive fields below 1 G. However, the saturation varied strongly with geometry, i.e., the less perforated structures M1–M3 saturated at ~150 G, whereas more complex structures M4, M6, and M7 required higher value of above 3000 G. Finite-element simulations showed that the effective magnetic induction was highest for the continuous and weakly grooved geometries, exceeding 1.4 T at high field for M1–M3, while M6 and M7 were limited to 0.8 T and 0.6 T, respectively. ME measurements under Helmholtz-coil excitation confirmed a strong dependence of output on geometry and field orientation. At resonance, M2 produced 17.5 mV at 97 kHz, compared with 15.2 mV for the continuous M1 sample. Under static-field excitation, M1 delivered 920 mV, while M2 and M3 reached 850 mV and 780 mV. Sensitivity analysis showed a maximum of 308.15 mV/Oe for M3, followed by 272.92 mV/Oe for M2 and 242.48 mV/Oe for M1, whereas M6 showed only 3.59 mV/Oe. The M3 sensor also exhibited low drift of about ±0.2 mV over 300 s and an estimated resolution of around 30 nT. These results show that controlled microstructuring of the FM layer is an effective route to improve flux concentration, reduce demagnetizing effects, and optimize ME sensor performance.