Abstract：NiFe₂O₄ferrite was prepared by sol-gel method. The microstructures, morphology, dielectric properties and electromagnetic properties were analyzed by XRD, FESEM and a vector network analyzer.Impedance matching solution maps were designed to obtain the matching frequency and matching thickness. Microwave absorption properties of the NiFe₂O₄single-layer absorber coating and double-layers composite ferrite absorbing coating were studied. The results show that a pure spinel structure of NiFe₂O₄is formed at 1 200 ℃. The NiFe₂O₄ samples have good frequency characteristics that both the real of permittivity and permeability is lower and the imaginary is larger, which are suitable for the production of matching layer. The minimum reflectance of the NiFe₂O₄single-layer absorber coating is-21 dB at 5.92 GHz. The bandwidth that reflectance lower than-10 dB reaches 3.2 GHz. The bandwidth of carbonyl iron-NiFe₂O₄double-layer composite coating reflectance lower than-10 dB reaches7 GHz when the thicknesses of NiFe₂O₄ and carbonyl iron are respectively 1.5 and 0.5 mm.

Keywords：NiFe₂O₄ ferrite; electromagnetic parameter; matching thickness; microwave absorbing property; absorber coating

中图分类号：TM25               文献标志码：A