The enhanced polarization relaxation and excellent high-temperature dielectric properties of N-doped SiC

The dielectric properties and microwave attenuation performance of N-doped SiC have been evaluated in 8.2-12.4GHz in the temperature range of 293-673K. The N doping dramatically improves the microwave absorption capability of SiC. The minimum reflection loss of N-doped SiC is enhanced to nearly -30dB with the effective absorption bandwidth [RL(dB) ≤ -10 dB] up to 3GHz at 673K. The excellent high-temperature dielectric properties are attributed to multi-relaxations, originated from the polarization relaxations of dipoles induced by the N doping and vacancy defects.