Electromagnetic properties and microwave absorption performances of nickel-doped SiCN ceramics pyrolyzed at different temperatures

Nickel-doped polymer derived SiCN ceramics (PDCs-SiCN (Ni)) were successfully prepared via a polymer-derived method from polysilazane and nickel oxide, and pyrolyzed at 900°C-1400 °C. The effects of pyrolysis temperatures on phase composition, microstructure and microwave absorption properties of PDCs-SiCN (Ni) were investigated. Results showed that the polymer-to-ceramic conversion was completed at around 800 °C. Besides carbon nanotubes were formed in the pore area of SiCN matrix through the catalysis of Ni. The electromagnetic (EM) parameters varied with the different pyrolysis temperatures. When the PDCs-SiCN (Ni) pyrolyzed at 1200 °C, the minimum reflection loss value reached −48.5 dB at 15.1 GHz, exhibiting the best EM wave absorption properties.