Preparation and microwave absorption properties of Ni(Co/Zn/Cu)Fe2O4/SiC@SiO2 composites

Ni(Co/Zn/Cu)Fe 2 O 4 /SiC@SiO 2 , a microwave absorber, was prepared by the sol–gel method. The phase structure and the morphology of the microwave absorbers were characterized by X-Ray Diffraction (XRD) and scanning electron microscopy (SEM), respectively. Laser sizer (LS) and X-ray photoelectron spectroscopy (XPS) analysis show the core–shell structure of SiC@SiO 2 . Coaxial method was used to measure the microwave absorption properties of the prepared composites in the frequency range of 2–18 GHz. When 70 wt% SiC is wrapped by 30 wt% SiO 2 , and 50 wt% NiFe 2 O 4 is added into 50 wt% SiC@SiO 2 , the as-prepared powders are found to have advanced microwave absorption properties with a minimum reflection loss (RL) of −32.26 dB at about 6.08 GHz, and the available bandwidth is approximately 2.1 GHz when the RL is below −10 dB.