Structural Design of FeCo/C Magnetic Nanocomposites:\nImplications Toward C‑Band Electromagnetic Wave Absorption

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