Enhanced EMW absorption properties of SiCN/Fe/Ni ceramics modified with Fe/Ni bimetal

The SiCN/Fe/Ni ceramics codoped with iron acetylacetonate (FA) and nickle acetylacetonate (NA) was synthesized by polymer-derived ceramics (PDCs) method in this study. The microstructure, phase composition and electromagnetic wave (EMW) absorption properties of the samples were analyzed. The polarization loss and conduction loss of materials were analyzed by the direct current (DC) multimeter and the contribution rate of polarization loss was more than 94% in the whole frequency band. The results showed that C, SiC, Fe2Si, Ni3Si, γ- (Fe, Ni) and CNTs were formed after pyrolysis which provided lots of heterogeneous interface and enhanced the interfacial polarization. Meanwhile, Ni could enter the lattice of Fe and formed a unique electronic configuration, which reinforced the conductivity and stability of Fe. In addition, the in-situ generated Fe2Si and Ni3Si provided magnetic loss and conduction loss. The RLmin value of SiCN/Fe/Ni-3 ceramic was −52.06 dB at 1.54 mm and the effective absorption band (EAB, RL ≤ −10 dB) reached 4.21 GHz (13.79–18 GHz, 1.43 mm).