fig6

Figure 6. Impedance gradient design strategies for broadband high-temperature absorption. (A) Macrostructure and cross-sectional SEM morphology, and (B) wave-absorption mechanism of alternating multilayered Si₃N₄/SiC aerogel. (A and B) are reprinted with permission from Ref.^[65]. Copyright © 2021, American Chemical Society; (C) Gradient impedance design concept comparing homogeneous and gradient aerogels, and (D) reflection loss of gradient impedance all-ceramic SiC/Si₃N₄ aerogel. (C and D) are reprinted with permission from Ref.^[51]. Copyright © 2025, American Chemical Society; (E) Genetic algorithm-optimized layer configurations, (F) reflection loss of multilayered structures, and (G) reflection loss of experimentally validated SiC@SiO₂ laminated aerogels. (E-G) are reprinted with permission from Ref.^[66]. Copyright © 2024, American Chemical Society. SEM: Scanning electron microscopy; EMW: electromagnetic wave.