目的 研发具有大宽厚比、高磁导率和低介电常数特性的片状微波吸收剂。方法 采用电沉积法制备高磁导率薄膜，经破碎，获得大宽厚比片状FeNiCo粒子，采用改进的溶胶凝胶法在其表面包覆完整致密的SiO2层。结果 基于大宽厚比及表面致密的包覆层，在较低填充量下即可获得高磁导率及较低的介电常数。在填充量(用质量分数表示)为50%时，能在1.3 GHz下实现−11.5 dB的强反射损耗(RL)和1.5 GHz的有效吸收带宽(RL<−5 dB)。结论 经包覆后吸收剂的磁导率不仅未降低，还得到显著提高。其原因是FeNiCo表面SiO2绝缘包覆壳层切断了粒子之间的导电网络，抑制了粒子之间的涡流效应。本研究为制备大宽厚比片状吸收剂及磁导率的提升提供了有效方法，为未来发展新型吸波材料提供了新的思路。

The work aims to obtain high permeability and low permittivity microwave absorbent with a large aspect ratio. High permeability films were prepared by electrodeposition method, followed by crushing the films into flake FeNiCo particles with a large aspect ratio. Finally, an improved sol-gel method was used to coat the surface with a complete and dense SiO2 layer. The coating layer based on the large aspect ratio and the dense surface, The dielectric constant with high permeability and low permittivity could be achieved at lower fillings. At a mass filling ratio of 50%, strong reflection loss (RL) of –11.5 dB at 1.3 GHz and an effective absorption bandwidth (RL<–5 dB) at 1.5 GHz were achieved. In conclusion, the permeability of the coated microwave absorbent does not decrease, but increases. This enhancement is attributed to the SiO2 insulation coating shell on the surface of FeNiCo, which cuts off the conductive network among particles and suppresses the eddy current effect among particles. This work provides an effective method for preparing flake microwave absorbent with a large aspect ratio and improving permeability, thereby offering insights for the development of future novel microwave absorbing materials.