Synergistic electrical and magnetic losses in Fe2O3/Cf composites with tunable conductivity for enhanced electromagnetic wave absorption

Electromagnetic wave (EMW) absorbing materials are crucial for electronics and health, but face challenges like impedance mismatch and limited EMW attenuation. Here, Fe 2 O 3 /carbon fibers (C f ) composites were synthesized via a one-step hydrothermal method using FeCl 3 ·6H 2 O and C f as raw materials. The phase composition and microstructure of Fe 2 O 3 /C f composites were systematically analyzed. The C f content was varied to regulate the electrical conductivity of Fe 2 O 3 /C f composites. Additionally, the effects of Fe 2 O 3 /C f content on electromagnetic (EM) parameters, conductivity, and EMW absorption characteristics of Fe 2 O 3 /C f /paraffin composites were investigated. The results indicate that with 18.42 wt.% C f , the Fe 2 O 3 /C f /paraffin composites exhibited the optimal electrical conductivity for EMW absorption. When the mass fraction of Fe 2 O 3 /C f is 30 wt.%, the Fe 2 O 3 /C f /paraffin composites achieved a minimum reflection loss (RL min ) of −34.38 dB with a thickness of 1.80 mm, and an effective absorption bandwidth (EAB, RL < −10 dB) of 4.06 GHz when the thickness is 1.60 mm, demonstrating notable advantages in both EAB/ d and RL min / d . This is due to appropriate C f content, which enables tunable electrical conductivity in the Fe 2 O 3 /C f /paraffin composites, leading to excellent impedance matching characteristics. Moreover, the synergism between magnetic and electrical losses effectively strengthens the EMW attenuation. This research provides a viable approach for producing high-efficiency EMW absorbing materials. • Tuning C f content in Fe 2 O 3 /C f optimizes impedance matching and EMW attenuation • Fe 2 O 3 /C f /paraffin achieves the RL min of −34.38 dB and EAB of 4.06 GHz (RL < −10 dB) • Synergistic mechanisms of conductive, dielectric, and magnetic losses were clarified