包覆镍铁氧体涂层的多孔陶瓷复合材料的制备与电磁性能

Preparation and electromagnetic properties of composites of porous ceramics coated with NiFe_2O_4

以多孔碳化硅陶瓷为基体,采用高分子凝胶法制备了包覆镍铁氧体涂层的多孔陶瓷复合材料。复合材料的结构、包覆涂层的表面形貌和电磁性能分别采用X射线衍射仪(XRD)、扫描电镜(SEM)和HP8510网络分析仪进行研究。结果表明,当锻烧温度为600℃时,在多孔陶瓷表面有立方晶系尖晶石结构的镍铁氧体晶相生成。随着包覆层数的增加,多孔陶瓷表面的镍铁氧体涂层的致密度和均匀性逐渐增强。与多孔陶瓷基体相比,包覆镍铁氧体涂层的多孔陶瓷的介电损耗角正切值tanδε减小,而磁损耗角正切值tanδμ增大,表现出较好的磁损耗特性,tanδμ值最大可达0.45。包覆镍铁氧体涂层的多孔陶瓷在X波段的tanδμ值随频率的升高呈减小趋势。

The composites of porous SiC ceramics coated with NiFe2O4 （NFPC） were prepared using the polyacrylamide gel method. The structural characteristics, morphology and electromagnetic properties of the composites were analyzed by X-ray diffraction （XRD）, scanning electron microscope （SEM） and HP8510 network analyzer. The results indicate that a pure spinel structure of NiFe2O4 forms on the porous ceramics （PC） at 600℃. The uniformity and consistency of the nickel ferrite coatings on porous ceramics increase with the increase of the layer number of coatings. NFPC exhibits lower dielectric loss tanδε and higher magnetic loss tanδε compared with the porous ceramics matrix. Its tanδε rises up to 0.45, which shows a better magnetic loss property. The tanδε of NFPC decreases with the frequency in X band.