Adjustable Iron‐Containing SiBCN Ceramics with High Temperature Microwave Absorption and Anti‐Oxidation Properties

Quaternary siliconboron carbonitride (SiBCN) ceramics show excellent high-temperature stability and oxidation resistance, indicating great potential as high-temperature electromagnetic (EM) wave absorbing materials. In this contribution, an efficient and facile method was developed to prepare bulk iron-containing SiBCN (Fe-SiBCN) ceramics with remarkable EM wave absorption at high temperature by pyrolyzing boron and iron containing precursors (PSZV-B-Fe). The introduction of boron and iron not only improves the high-temperature stability but also influences the complex permittivity and EM wave absorption. The minimum reflection coefficient (RCmin) is -61.05 dB, and the effective bandwidth absorption (EAB) is 3.35 GHz (9.05-12.4 GHz). The RCmin will be decreased to -52.3 dB at 600 degrees C as well as the EAB covers more than 67% of the X band (2.8 GHz). The high-temperature stable Fe-SiBCN ceramics with adjustable dielectric properties can be utilized as high-performance EM wave-absorbing materials in high-temperature and harsh environments.