Excellent microwave absorption performance of PAN-based Fe/C nanofibers with low loading fillers

Carbon/magnetic metal composites have attracted great interest in the microwave absorption field. Here, polyacrylonitrile (PAN)-based Fe/C nanofibers were fabricated through electrospinning in combination with high-temperature carbonization, which was used as difunctional dielectric and magnetic microwave absorbing materials. The Fe/C nanofibers fabricated were characterized by a high aspect ratio, and magnetic Fe nanoparticles had uniform distribution within dielectric carbon fibers. The Fe/C nanofibers had prominent performance in absorbing microwave because of favorable impedance matching condition, improved capability in attenuating microwave and synergistic influence between dielectric loss of PAN-based carbon materials and magnetic loss of Fe, which was correlated with the carbonization temperature as well as Fe content. The optical Fe content of 5 wt%, carbonization temperature of 1200 ℃, Fe/C/paraffin composites containing 10 wt% fillers had high performance in absorbing microwave, the reflection loss reaching the maximum of |RLmax| = 40.47 dB at 9.36 GHz at 2.5 mm matching thickness, as well as the effective bandwidth (EAB) of 4.64 GHz (13.36–18 GHz), covering 12.88–16.88 GHz at 1.6 mm thin thickness, which nanofibers were easy to obtain and were characterized by strong performance in absorbing microwave, thin thickness and light weight. Thus, the fabricated nanofibers can be recognized as a promising microwave absorber.