Abstract
The development of electromagnetic wave absorbers, which have widespread application prospects, requires new lightweight, multifunctional materials that can be used in harsh environments. Herein, ultralight SiC/Si3N4 aerogels are prepared by freeze-drying and carbothermal reduction reaction, and their microstructures were investigated by transmission electron microscopy, Raman spectroscopy, and X-ray absorption near-edge structure at the N K-edge. The result of morphology analysis indicates that the porous structure of SiC/Si3N4 aerogels are composed of SiC and Si3N4 nanowires. The optimal prepared SiC/Si3N4 aerogel possesses high absorption performance with a minimum reflection loss of ? 25 dB and a wide effective absorbing bandwidth of 4.3 GHz (6.1–10.4 GHz) at a thickness of 3.97 mm. Such superior absorption performance is due to excellent impedance matching and enhanced polarization loss. Moreover, the SiC/Si3N4 aerogel is thermostable under air atmosphere below 1100 °C, which can be attributed to the presence of Si3N4. These achievements suggest that SiC/Si3N4 aerogel is promising candidate for electromagnetic wave absorption in harsh environment.
NSTL
Elsevier