Multi-Layer Magnetic Shields Based on Fe-Based Nanocrystalline and Co-Based Amorphous Ribbons

We constructed a multi-layer composite magnetic shield composed of Fe-based nanocrystalline (FN) and Co-based amorphous (CA) ribbons, and focused on the influence of the number of layers and their arrangement on the shielding effectiveness (SE). Finite element analysis (FEA) and layer-by-layer inversion calculations were performed to analyze the attenuation process of the magnetic field between shield layers. Increasing the number of shield layers improves the maximum value of SE (SE_max) and significantly broadens the working range (WWR). In a weak magnetic field, CA exhibits higher shielding performance, whereas FN is better in a strong magnetic field. The FN/FN/CA combination (FN is closer to the field source) exhibits an SE_max of up to 51.7 dB within a WWR of 674.3 A/m, and demonstrates a 14.4% improvement in SE compared to FN/FN/FN combination across the entire tested magnetic field range. Finally, a gradient layering design is proposed that enables each layer to operate within its optimal permeability range, thereby improving the overall SE and broadening the effective working magnetic field range.