High-performance electromagnetic wave absorption of porous honeycomb-like FeNi/C composites at 2-18 GHz

The FeNi/C composites were prepared by co-precipitation and high-temperature calcination. FeNi alloy particles are inlaid uniformly in the carbon matrix, forming a unique porous honeycomb structure and effectively regulating impedance matching. More importantly, the synergistic attenuation mechanism of dielectric loss and magnetic loss promotes the efficient attenuation of the FeNi/C composites to electromagnetic (EM) waves (EMWs). The minimal reflection loss (RLmin) of S3 is - 53.67 dB at 2.5 mm, and the effective absorption bandwidth (EAB) is as high as 2.64 GHz. Combined with the morphology and structural composition of the prepared materials, the microwave absorption (MA) mechanism consists of multiple loss mechanisms, such as eddy current loss caused by FeNi component, dipole polarization caused by carbon defect and oxygen-containing polar group, and conduction loss caused by carbon matrix. The research results provide the theoretical and experimental basis for the further design of efficient and low-cost electromagnetic wave absorbing materials.

Automated summary

The FeNi/C composites were synthesized by co-precipitation and high-temperature calcination, with FeNi alloy particles uniformly embedded in a carbon matrix to form a unique porous honeycomb structure, resulting in effective impedance matching. The synergistic attenuation mechanism of dielectric loss and magnetic loss contributes to the efficient absorption of electromagnetic waves by the FeNi/C composites. The research provides a theoretical and experimental basis for the design of efficient and low-cost electromagnetic wave absorbing materials.