Ni-decorated SiC powders: Enhanced high-temperature dielectric properties and microwave absorption performance

Ni-decorated SiC powders were fabricated by using an improved solution chemical method. The dielectric properties were investigated in the temperature range of 373-673. K at frequencies of 8.2-12.4. GHz (X-band). Compared to the naked SiC, the complex permittivity and loss tangent of Ni-decorated SiC are significantly improved in the frequency and temperature ranges investigated. Strong temperature-dependent loss tangent associated with the hopping conductance between Ni nanoparticles in the modified layers is observed in the Ni-decorated SiC. Calculation of the microwave absorption shows that much enhanced absorption performance can be observed in the Ni-decorated SiC. Increased microwave absorption coupled with widened effective absorption bandwidth demonstrates positive temperature effects on the absorption performance, indicating promising potential applications of high-temperature microwave absorption materials.