Evolution of Fe Single Atom in SiOC Ceramic Fibers and Their High‐Temperature and Ultrathin Electromagnetic Wave Absorption

) and adjacent N/C atoms, the local microstructure symmetry of SiOC is disrupted, which improves the polarization behavior of SiOC─Fe─CN and enables multiple polarization loss mechanism. Notably, the SiOC─Fe─CN-10 fiber exhibits exceptional absorption capability with a reflection loss (RL) of -59.33 dB at an ultrathin thickness of 1.60 mm and -58.0 dB at a low-frequency of 5.93 GHz. The effective absorption bandwidth (EAB) reaches 5.5 GHz at a thickness of 1.49 mm. It also delivers remarkable high-temperature (≥500°C) EMW absorption performance, with an RL of -53.2 dB at a low-frequency of 4.78 GHz, which is the high performance of SiC-based high-temperature absorbers currently available. Moreover, the SiOC─Fe─CN-10 composite demonstrates favorable thermal diffusion properties. This concept of precise control over particle state provides a valuable strategy for the design of high-performance EMW absorbers and promotes the ongoing advancement of electromagnetic technology.