克服Snoek极限、改善电磁频散特性是磁性纳米吸波材料发展面临的关键问题。利用强磁场对物质极强的磁能作用优化组织结构，有望实现电磁性能突破。本课题拟基于海藻酸纤维“蛋-盒”结构对金属离子的络合作用，在强磁场下制备FeCo/CoFe2O4磁耦合单元多壳层纤维，利用强磁场调控软磁相和硬磁相比例、晶粒取向、尺寸与分布、晶格结构、缺陷结构、界面结构等，在原子尺度揭示磁化能对纤维组织结构的调控机制；研究纤维组织结构变化和磁交换耦合作用对高频磁导率、高频介电常数、磁共振和极化驰豫的调控规律，阐明强磁场效应-微观结构-电磁性能的关联机理，建立突破Snoek极限并改善频谱特性的强磁场策略。基于上述研究，开展强磁场下图案化多层吸波薄膜制备，结合微磁学和有限元方法阐明纤维间偶极作用、电磁各向异性、排列周期性对高频电磁性能的影响机制，通过优化多层结构提高阻抗匹配与电磁损耗，为改善宽频域综合吸波性能提供理论参考。

Magnetic nanomaterials represent a new generation of microwave absorbing materials. Overcoming the Snoek limit and improving the electromagnetic dispersion characteristics are the key issues to be solved urgently at present. The method of high magnetic fields is expected to break through the bottleneck of electromagnetic performance. In this project, the applicant intends to use alginate nanofiber to coordinate Fe/Co ions and further prepared FeCo/CoFe2O4 multi-shell fibers under a high magnetic field. Through adjusting the phase ratio, crystalline, grain size/ orientation/distribution, defect, and interface, we will demonstrate the mechanism of magnetization on fibrous tissue structure at the atomic scale, study the regulation of fibrous structure changes and magnetic exchange coupling effects on high-frequency permeability, permittivity, magnetic resonance, and polarization relaxation, clarify the strong magnetic field effect-microstructure-electromagnetic performance relationship, and establish a strong magnetic field strategy to breakthrough Snoek limit and improve electromagnetic dispersion characteristics. Based on the above studies, the preparation of patterned multi-layered absorber films under high magnetic fields was developed. Microelectromagnetics and finite element methods were used to elucidate the mechanism of dipole interaction, electromagnetic anisotropy, and periodicity of arrangement on high-frequency electromagnetic performance. We will optimize the multi-layer structure to improve impedance matching and electromagnetic loss, and improve the comprehensive microwave absorption performance in a wide frequency range.