Authors: Y.K. Dou, H.B. Jin
Affilation: Beijing Institute of Technology, China
Pages: 306 - 309
Nanopowders of aluminum and nitrogen codoped β-silicon carbide (β-SiC) were successfully produced by self-propagating high-temperature synthesis in a nitrogen atmosphere. Characterizations by X-ray diffraction and scanning electron microscopy demonstrate the formation of Al-N codoped β-SiC nanopowders. In 1 MPa N2 atmosphere, the X-ray analysis of the produced powders suggests that Al and N are accommodated in the lattice of SiC, which enlarges with increasing amounts of Al. The electric permittivities of prepared powders have been determined in the frequency range of 8.2-12.4 GHz. They have been decreased by the Al and N co-doping compared to that of SiC with Al doping. But with the increasing the amounts of Al, the electric permittivities of the SiC nanopowders are increased again. The paper presents a method to adjust dielectric property of SiC powders in the GHz range. These features confer Al-N codoped β-SiC qualifications of the important microwave absorbing material.