Electromagnetic wave absorbing properties of SiC/SiO₂ composites with ordered inter-filled structure

Silicon carbide/silica (SiC/SiO₂) monoliths with ordered inter-filled structure were prepared via nanocasting and cold-pressing, using polycarbosilane as precursor and ordered mesoporous silica SBA-15 as template. The SiC grains were incorporated, in form of ordered rodlike arrays, into nanochannels of SBA-15. Their electromagnetic (EM) wave absorbing properties were investigated in X-band, in which SiC acted as EM wave absorber and SiO₂ as transparent matrix. The results indicated that the composites had good EM absorbing properties due to the enhanced dielectric loss resulting from their intrinsic physical properties and special structures. The optimal absorbing properties were determined by impedance match and quarter-wavelength law.