Structural Design of FeCo/C Magnetic Nanocomposites: Implications Toward C-Band Electromagnetic Wave Absorption

The rapid advancements in radar and electromagnetic communication technologies have sparked a pressing need for thin, lightweight, and highly efficient low-frequency electromagnetic absorbing materials (EAMs) tailored for the C-band. However, the close linear correlation between the real and imaginary permittivity components of EAMs at low frequencies hinders the decoupling of wave impedance and electromagnetic dissipation, posing a formidable challenge in achieving a satisfactory absorption performance. In this study, a strategy for targeting C-band absorption encompassing advancements in material design and structural engineering has been formulated. Leveraging the high-efficiency microwave plasma-assisted reduction chemical vapor deposition (MPARCVD) technique, FeCo/C magnetic nanocomposites were successfully synthesized, offering a cost-effective and energy-saving solution. The growth of carbon microspheres on the FeCo alloy particle surfaces significantly regulated the real and imaginary permittivities within a broad range, attributed to the drastic improvement in interfacial polarization and electrical conductivity. This versatile platform facilitated structural engineering, enabling the design and optimization of the impedance matching layer and wave absorption layer. Notably, our strategy achieved a minimal reflection loss of −36.8 dB, along with an effective absorption bandwidth spanning from 3.84 to 12 GHz, covering both the C-band and the X-band. This work provides a strategy for attaining superior microwave absorption performance in the C-band, opening up promising avenues for applications in electromagnetic interference shielding and stealth technology tailored for the C-band frequency range.