Effect of boron doping on microwave dielectric properties of SiC powder synthesized by combustion synthesis

Research highlights: → In this study, B-doped SiC solid solution was synthesized via combustion synthesis in nitrogen atmosphere, and the relations between phase component, microstructure and dielectric properties of the products were investigated. The mechanism of microwave dielectric loss by B doping was discussed. - Abstract: Boron-doped SiC powders were synthesized from the Si/C/B system in a nitrogen atmosphere by combustion synthesis. Results showed that boron benefited the crystallization of β-SiC, and that SiC solid solution with B acceptor doping was generated in combustion process. In the frequency range of 8.2-12.4 GHz, it was found that both real part ε' and imaginary part ε'' of complex permittivity of SiC samples decreased firstly, and then increased with increasing B content.