Fabrication of Fe/C Composites as Effective Electromagnetic Wave Absorber by Carbonization of Pre-magnetized Natural Wood Fibers

With the increasing usage of varied electronic devices, the induced electromagnetic interference (EMI) irradiation pollution has become a novel environmental pollution besides of water and air pollutions, drawing a great of interests from the scientists to address EMW radiation problem via designing various electromagnetic wave (EMW) absorbers, which is supposed to be with light weight, thin thickness, wide effective absorbing bandwidth and strong absorbing capacity. One kind of the most attractive absorbers is magnetic carbon composites. Here, we successfully synthesized porous structural C/Fe composites by in-situ carbonization of pre-prepared Fe 3 O 4 /wood fibers at 1000°C. The EMW absorption property of C/Fe composites is excellent with a minimum RL value of -32.67 dB at 9.86 GHz, a matching thickness of 2.2 mm and a wide response bandwidth of 14.5 GHz. This excellent absorption performance is proved to be due to the continuous network of Fe 3 O 4 /Fe/ Fe 3 C hybrids, permitting optimal impedance matching, the strongest dielectric loss and the optimal magnetic loss. Moreover, the interface polarizations at Fe-Fe 3 C and Fe 3 O 4 -Fe interfaces, are positive to improve the microwave absorption performance.