Microwave absorption performance of PDCs-SiCN(Fe) ceramics with negative imaginary permeability

PDCs-SiCN(Fe) ceramics were successfully fabricated with different content of ferric acetylacetonate (FA) by polymer-derived method. The effects of FA on the phase composition, microstructure, resistivity, dielectric properties, magnetic properties and microwave absorption properties of PDCs-SiCN(Fe) ceramics in the range of 2-18 GHz were investigated. The samples presented amorphous structure with a few crystalline phases of α-Fe and free carbon in the gaps, which were expected to be good soft magnetic materials. The average real permittivity and imaginary permittivity of PDCs-SiCN(Fe) ceramics with 50 wt% FA was about 14.1 and 5.3 respectively. Furthermore, the PDCs-SiCN(Fe) ceramics with 50 wt% FA addition content showed the broad absorption bandwidth in the 5.1-8.4 GHz with RL ≤ −10 dB (> 90% absorption) at 4 mm.