The effect of MWCNTs on the microwave electromagnetic properties of ferrite–MWCNTs composites

BaZn_1.2Co_0.8Fe₁₆O₂₇ ferrites were synthesized by a combined citrate–EDTA complexing method, and then the ferrites were mixed with multi-walled carbon nanotubes (MWCNTs) to prepare microwave absorbing composites. The morphology of ferrites and MWCNTs were observed using SEM. The microwave electromagnetic properties of ferrite–MWCNTs composites have been measured by a network analyzer (Agilent 8722ET) in the frequency range of 2–18 GHz. The theoretical reflection loss (RL) values of the composites were obtained according to the transmission line theory. In this work, the ferrite–5 wt% MWCNTs composite obtained a thinner matching thickness of 0.8 mm, with a RL maximum of −10 dB and absorption band (less than −5 dB) from 7 to 15 GHz, being promising microwave absorbing material.