Preparation and microwave absorption properties of Fe-doped SiC powder obtained by combustion synthesis

Fe-doped SiC powders were synthesized via combustion reaction of the Si and C system in a 0.1 MPa nitrogen atmosphere using iron as the dopant. The prepared powders have fine spherical particles and narrow particle size distribution. The electric permittivities of SiC samples were determined in the frequency range of 8.2-12.4 GHz. Results show that the permittivity of SiC increases with the increasing iron contents. The 5% Fe-doped SiC powder with 2 mm or 2.5 mm thickness exhibits the best microwave absorption over the frequencies ranging from 8.2 to 12.4 GHz.