Open Ceramics (Sep 2023)
The dielectric properties of polymer derived silicon oxycarbonitride film incorporated with TiO2 for electromagnetic wave absorption
Abstract
The polysilazane preceramic precursor is applied as a coating on ceramic substrates and pyrolyzed at different temperatures to form a silicon oxycarbonitride ceramic film for its dielectric properties in the low-frequency range of 1–8 MHz. Additionally, the porous ceramic hollow matrix filled with the polysilazane preceramic precursor is pyrolyzed for dielectric measurement in the high-frequency range of 1–19 GHz. The results indicate that coating Al2O3 substrates with SiCNO reduces the absorption effect as the pyrolytic temperatures increase. Conversely, coating AlN substrates with SiCNO exhibits the opposite absorption effect. Incorporating titanium dioxide with SiCNO reduces the wave absorption effect within the temperature range of 700 °C–1100 °C. The loss tangent and electromagnetic wave loss of the porous ceramic hollow matrix filled with SiCNO are 4.06 × 10−2 and 4.41 × 10−2, respectively in the high-frequency range. These findings indicate the electromagnetic wave absorption ability of SiCNO composite.
