Preparation and electromagnetic wave absorption properties of carbon nanotubes loaded Fe3O4 composites

Carbon nanotubes loaded Fe₃O₄ (CNTs-loaded Fe₃O₄) composites synthesized via a common chemical vapor deposition method showed excellent electromagnetic wave absorption performance. The effect of different Fe₃O₄ content on the electromagnetic parameters and wave absorption properties of the CNTs-loaded Fe₃O₄ composites was investigated. The results indicated that the CNTs-loaded Fe₃O₄ composites with the content of 42.4% Fe₃O₄ exhibited the best absorption property among the as-synthesized CNTs-loaded Fe₃O₄ composites. The minimum RL value reached -35.9 dB at 7.12 GHz with a thickness of 3 mm. More significantly, the effective bandwidth less than -10 dB was 4.32 GHz with a thickness of 1.5 mm. Compared with pure CNTs or Fe₃O₄, the impedance matching of CNTs-loaded Fe₃O₄ composites is markedly improved. The absorbing mechanism is mainly due to the synergistic effect of improved impedance matching, interface scattering, dielectric loss and magnetic loss. CNTs-loaded Fe₃O₄ composites with excellent electromagnetic wave absorption performance contribute to the development of light and highly efficient electromagnetic wave absorbing materials.