Synthesis and enhanced microwave absorption performance of CIP@ SiO2@Mn0.6Zn0.4Fe2O4 ferrite composites

Abstract

Novel core@shell@shell structured carbonyl iron powder (CIP)@SiO2@ Mn0.6Zn0.4Fe2O4 ferrite composites having great microwave absorption characteristics were successfully synthesized using chemical co-precipitation. The microstructure, morphology and microwave absorption performance of CIP@SiO2@Mn0.6Zn0.4Fe2O4 ferrite composites were systematically investigated. The results show that both coating layers of SiO2 and Mn0.6Zn0.4Fe2O4 are uniform and fine. The prepared CIP@SiO2@Mn0.6Zn0.4Fe2O4 composites in this study display better dielectric loss and frequency characteristic at high frequency than CIP, CIP@SiO2 and CIP@Mn0.6Zn0.4Fe2O4. The results of electromagnetic parameters also indicate that the enhanced microwave absorption performance primarily originates from the substantial contributions of magnetic loss to reflection loss. The optimal value of reflection loss of CIP@SiO2@Mn0.6Zn0.4Fe2O4 having the thickness of 2 mm can reach up to −44.24 dB at 11.57 GHz as well as the bandwidth (RL ≤ −10 dB) from 9.04 to 16.16 GHz among the frequency range from 2 to 18 GHz. In addition, the greatly enhanced microwave absorption performance is attributed to good wave impedance matching, high attenuation constant, multi-relaxation processes and multiple interfacial polarization.