Key Takeaways & Executive Findings
- •• • FeNiCo/CNF composites achieve a minimum reflection loss (RLmin) of −55.5 dB at 14.24 GHz with an ultrathin matching thickness of 1.6 mm, demonstrating exceptional absorption efficiency critical for lightweight stealth applications. • • The (FeNi)3Co2/CNF composite exhibits optimized impedance matching and magnetic-dielectric synergy, enabling effective electromagnetic energy dissipation across a broad frequency range, essential for practical radar absorption. • • Electrospinning enables precise control of coercivity and permeability through systematic modulation of magnetic metal composition, allowing tailored electromagnetic properties for specific frequency bands. • • Radar cross-section (RCS) simulations confirm significant RCS reduction across a wide angular range, validating the material's potential for stealth technology and electromagnetic interference mitigation.
Abstract
The proliferation of electronic devices has intensified electromagnetic radiation pollution, necessitating advanced microwave absorption materials. This study presents the electrospinning fabrication of FeNiCo/carbon nanofiber (FeNiCo/CNF) composites with exceptional microwave absorption properties. The FeNiCo/CNFs achieved a minimum reflection loss (RLmin) of −55.5 dB at 14.24 GHz with an ultrathin matching thickness of only 1.6 mm. Microstructural analysis and electromagnetic parameter testing revealed that the superior absorption stems from the synergistic interaction between the carbon nanofiber network and FeNiCo alloy nanoparticles, which promotes multiple reflections and efficient energy dissipation. The precise control of coercivity and permeability via systematic modulation of magnetic metal composition enabled enhanced impedance matching and optimized magnetic-dielectric synergy. Furthermore, radar cross-section (RCS) simulations confirmed the material's capability to significantly reduce RCS values across a wide angular range, validating its potential for stealth technology applications. This work introduces a cost-effective and sustainable approach for developing ultralight, high-performance microwave absorbers, addressing the limitations of conventional materials such as high density and poor stability.
1. Introduction
The rapid advancement of electronics and wireless devices has escalated electromagnetic radiation (EMR) pollution, posing risks to human health and the reliability of communication and precision equipment. Conventional microwave absorbers, such as ferrites and magnetic metal powders, suffer from high density, poor thermal stability, and susceptibility to oxidation, limiting their practical deployment. Carbon materials offer low density and corrosion resistance but exhibit high dielectric constants and negligible permeability, leading to impedance mismatch and skin effect that degrade absorption performance.
To overcome these bottlenecks, this study introduces FeNiCo/carbon nanofiber (FeNiCo/CNF) composites fabricated via electrospinning. By integrating magnetic FeNiCo alloy nanoparticles into a conductive carbon nanofiber network, the composite achieves a synergistic balance between dielectric and magnetic losses, enabling superior impedance matching and efficient microwave dissipation. The experimental results demonstrate an exceptional RLmin of −55.5 dB at 14.24 GHz with an ultrathin thickness of 1.6 mm, addressing the critical need for lightweight, high-performance absorbers suitable for stealth technology and EMR mitigation.
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YUAN Wenpei, QU Lin, WANG Yajing, LIU Pengyu, ZHANG Yanlan, WANG Yongzhen (2026). Electrospinning of FeNiCo/carbon nanofibers: a new paradigm for lightweight microwave absorbers. New Carbon Materials. https://doi.org/10.1016/S1872-5805(26)61075-X
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Frequently Asked Questions
What is the maximum reflection loss achieved by the FeNiCo/CNF composites and at what frequency and thickness?
The FeNiCo/CNF composites achieve a minimum reflection loss (RLmin) of −55.5 dB at 14.24 GHz with a matching thickness of only 1.6 mm, indicating excellent absorption efficiency in the Ku-band.
How does the composition of the FeNiCo alloy affect the electromagnetic properties and absorption performance?
Systematic modulation of the magnetic metal composition allows precise control of coercivity and permeability, which optimizes impedance matching and magnetic-dielectric synergy. The (FeNi)3Co2/CNF composite exhibits the best absorption performance, achieving an RLmin of −55.5 dB.
What are the primary loss mechanisms contributing to the microwave absorption in FeNiCo/CNF composites?
The absorption is attributed to the combined effects of interfacial polarization, dipole polarization, natural resonance, eddy current loss, and conductive loss. The carbon nanofiber network provides conductive pathways and multiple reflection sites, while the FeNiCo alloy enhances magnetic losses.
How does the material's radar cross-section (RCS) reduction performance compare to conventional absorbers?
RCS simulations confirm that FeNiCo/CNF composites significantly reduce RCS values across a wide angular range, indicating superior radar stealth capability compared to conventional absorbers, which often suffer from impedance mismatch and limited bandwidth.
What are the scalability and cost implications of the electrospinning method for industrial production?
Electrospinning is a cost-effective and scalable technique for producing continuous nanofibers. The use of earth-abundant metals (Fe, Ni, Co) and carbon precursors further enhances cost-effectiveness, making the process viable for large-scale manufacturing of lightweight microwave absorbers.
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