[Advanced Functional Materials] Hierarchical Heterogeneous Co-based Magnetic Absorbers for Superior Broadband High-efficiency Microwave Absorption
writer：Yixuan Han, Yuren Yang, Tonghua Li, Yali Zhang*, Hua Guo, Mukun He, Kehua Han*, Hua Qiu, Junwei Gu*
keywords：Hydrothermal synthesis, Co-based microwave absorber, Broad-band microwave absorption, Radar cross-section simulation
source：期刊
Issue time：2025年
Yixuan Han, Yuren Yang, Tonghua Li, Yali Zhang*, Hua Guo, Mukun He, Kehua Han*, Hua Qiu, Junwei Gu*. Hierarchical Heterogeneous Co-based Magnetic Absorbers for Superior Broadband High-efficiency Microwave Absorption, Advanced Functional Materials, 2025, 10.1002/adfm.202525719. 2024IF=19.0.（1區材料科學Top期刊）
https://advanced.onlinelibrary.wiley.com/doi/10.1002/adfm.202525719
Abstract
Microwave absorbing materials are crucial for digital industries, communication networks, and stealth technology. However, precise microwave absorption performance control through microstructure design remains challenging. Herein, a strategy based on multiple equilibrium/competitive reactions is developed to fabricate Co-based microwave absorbers with tunable morphologies. The core–shell spherical cobalt (CS-SC) exhibits superior microwave absorption performance due to optimized impedance matching and interfacial effects. It achieves an effective absorption bandwidth (EAB) of 8.3 GHz (9.7–18.0 GHz) at 2.1 mm thickness, with a minimum reflection loss (RLmin) of -51.6 dB. Radar cross-section (RCS) simulations confirm a low RCS (＜-20.0 dB·m2) over incident angles from -90° and 90°. This work provides novel insights into the microstructural engineering of magnetic absorbers via solvothermal methods and the strategic modulation for their microwave absorption performance.
電磁波吸收材料在數字化產業、通訊網絡和特種裝備隱身等快速發展的領域中發揮著關鍵作用。然而，如何通過精細的微觀結構設計實現電磁波吸收材料電磁波吸收性能的有效提升和精準調控，仍然面臨諸多挑戰。本文提出一種基于同一Co前驅體，通過多重平衡/競爭反應調控Co基磁性電磁波吸收劑的相組成、形貌及微觀結構的方法，實現其寬頻強電磁波吸收性能的可控調節。具體地，采用乙二醇溶劑熱法制備了球狀（SC）、核殼球狀（CS-SC）、片狀（FC）和核殼片狀（CS-FC）Co基磁性電磁波吸收劑。其中，CS-SC因其磁芯-介電殼結構提高的阻抗匹配特性及獨特的界面效應，具有強而寬的電磁波吸收性能。當CS-SC質量分數為25 wt%時，其復合材料在2.1 mm處有效吸波帶寬（EAB）高達8.3 GHz（9.7 GHz～18.0 GHz），對應最小反射損耗值（RLmin）為-51.6 dB，優于SC（2.7 GHz，-19.2 dB）、FC（1.0 GHz，-19.9 dB）和CS-FC（4.9 GHz，-33.6 dB）。此外，模擬仿真結果表明，CS-SC對寬入射角度（-90o到90o）電磁波均有極小的雷達散射截面積（RCS）（＜-20.0 dB·m2），優于SC（-9.0 dB·m2）、FC（-8.3 dB·m2）和CS-FC（-6.8 dB·m2），具有最佳的實際應用價值。本工作為溶劑熱法合成磁性電磁波吸收劑的微觀結構設計制備與電磁波吸收特性調制提供了新的思路。