Microwave absorbing performance of polymer-derived SiCN (Ni) ceramics prepared from different nickel sources.

A series of nickel-containing polymer-derived SiCN ceramics (PDC-SiCN (Ni) ceramics) were successfully prepared from different nickel sources following a polymer-derived method. The scanning electron microscopy (SEM) and transmission electron microscope (TEM) were used to peruse the microstructure of the ceramics. The electromagnetic and microwave absorption properties of PDC-SiCN (Ni) ceramics in the 2–18 GHz range were investigated. Results showed that the Ni nanoparticles in ceramics were dispersed in the amorphous SiCN matrix and the synergetic effect of dielectric and magnetic loss enhanced electromagnetic attenuation of the materials. The optimal reflection loss (R L ) was found for the PDC-SiCN (Ni) ceramics with Ni powders as nickel source, being −78.6 dB at 17.1 GHz when the thickness was 3.5 mm and the bandwidth of RL below −10 dB (90% absorption) was 1.6 GHz. It meant that the PDC-SiCN (Ni) ceramics might exhibit a promising prospect as microwave absorbing materials. [ABSTRACT FROM AUTHOR]