Efficient ferrite/Co/porous carbon microwave absorbing material based on ferrite@metal–organic framework

A series of ferrite/Co/porous carbon materials were prepared by the situ-thermal carbonization of ferrite/ZIF-67 under N2 atmosphere, and the microwave absorption properties have also been investigated. The magnetoelectric synergistic microwave absorbing material is promising as an efficient microwave absorbing material. The component absorbers with unique porous carbon structure make great contribution to the impedance match, interface polarization, magnetoelectric synergistic effect, and multiple reflection and scattering loss. The carbonization temperature indicates a crucial effect on the porous structure, and too high temperature will result in the collapse of the porous structure. The ferrite/Co/porous carbon fabricated at 500 °C (FC500) exhibits the most enhanced microwave absorbing performance. The maximum reflection loss (RL) of FC500 reaches −31.05 dB at 14.32 GHz, and the effective absorption bandwidth (RL ≤ −10 dB) is 4.8 GHz (12.24 GHz–17.04 GHz) corresponding to a thickness of 1.5 mm. The maximum reflection loss (RL) can reach −47.31 dB at 8.4 GHz, and absorption bandwidth (RL ≤ −10 dB) is 2.72 GHz (6.80 GHz–9.52 GHz) with a thickness of 2.5 mm. Thus, the component absorption materials can significantly decrease the weight of ferrite absorbers, ascribing to the thinner optimum thickness.