Layer Number Engineering of Metglas in PZT/Metglas Laminated Magnetoelectric Sensors: Balancing High Coupling Coefficient and Ultra‐Low Detection Limit

Reconciling a high magnetoelectric (ME) coupling coefficient with low noise levels in PZT/Metglas sensors remains a significant challenge. This study methodically examines the impact of Metglas layer count on the performance and magnetic loss mechanisms of sensors consisting of multiple Metglas layers and a single PZT‐5H layer. Experimental results demonstrate that layer count significantly influences resonant frequency and DC bias dependence, with the latter caused by the magnetic flux shielding effect. The 5‐layer Metglas configuration exhibits the most favorable overall performance, with the magnetoelectric coupling coefficient () attaining 415 V/(cm·Oe) (8.3 × 10 4 V/T), limit of detection (LOD) as low as 25 pT. Furthermore, this configuration maintains a stabilized flat noise in the non‐resonant region at . This work establishes a theoretical and experimental foundation for designing high‐sensitivity, low‐noise ME sensors for weak magnetic field detection.