Preparation and electromagnetic wave absorption properties of Fe-doped zinc oxide coated barium ferrite composites

Fe-doped zinc oxide (ZnO) coated barium ferrite composite particles were prepared by a heterogeneous precipitation and thermal treatment process. The prepared composite particles were characterized with X-ray diffraction (XRD) and transmission electron microscopy (TEM). The complex relative permittivity and permeability of ZnO/barium ferrite composites were measured in the frequency range of 2–12 GHz. The results show that the coverage of ZnO has a great influence on microwave response of barium ferrite particles. The formation of a ZnO thin layer on the surface of a barium ferrite particle changes the character of the frequency dispersion of the complex relative permittivity and permeability. By changing the thickness of ZnO coverage, the frequency dependence of the microwave electromagnetic and absorbing properties could be adjusted, which provides us an opportunity for the synthesis of tailored particles.