Synthesis and Microwave Absorption Property of the Core-shell Absorber with Hollow Cenosphere as Core

ABSTRACT Core-shell material with hollow cenospheres of low density as the core has been synthesized by depositing a layer of iron oxide shell on the surface of seed hollow cenospheres. The phase structure, morphology, particle size, chemical composition, and magnetic properties of the synthesized material have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), and vibrating sample magnetometer (VSM). Results confirm the coating of iron oxide on hollow cenospheres. Electromagnetic characterization of synthesized core-shell material was carried out in X band. Dilectric loss (tanδe) and magnetic loss (tanδm) were found in the range of ∼ 0.2 and 0.05, respectively, over 8–12 GHz. Simulation studies show the effective reflection loss (RL) is more than 10 dB over frequency range 9–10.5 GHz at a thickness of 2.2 mm. The low density iron oxide coated cenospheres have potential applications as microwave absorbing materials.