Strong attenuation capability and good impedance matching are necessary conditions for high-performance electromagnetic wave (EMW) attenuation materials, which are difficult to balance in the polymer-derived ceramics (PDCs) preparation process. In this work, the dielectric loss phase and wave-transparent phase are simultaneously obtained in SiBCN ceramics, endowing a strong EMW absorbing capability. The results show that the transformation of Si₃N₄ to SiC could be controlled to achieve coexistence in SiBCN ceramics. The Si₃N₄ improves the impedance matching characteristics, while SiC and the corresponding heterogeneous interfaces enhance the polarization loss capability. Furthermore, the graphite strips construct a three-dimensional conductive network to improve the conductive loss capability. As a result, the minimum reflection loss reaches -54.24 dB at 15.04 GHz, and the effective absorption bandwidth is 7.48 GHz with a thickness of 1.72 mm, covering the whole Ku band. The excellent EMW absorption capability of SiBCN ceramics can be attributed to the synergistic function of Si₃N₄ and SiC, which provides a novel strategy for the preparation of ultra-thin and strong EMW attenuating materials with broadband.

中文翻译：

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可控相变增强 SiBCN 聚合物衍生陶瓷的电磁波衰减

强大的衰减能力和良好的阻抗匹配是高性能电磁波 （EMW） 衰减材料的必要条件，这在聚合物衍生陶瓷 （PDC） 制备过程中难以平衡。在本工作中，SiBCN 陶瓷同时获得了介电损耗相和透波相，赋予了强大的 EMW 吸收能力。结果表明，可以控制 Si₃N₄ 向 SiC 的转变，以实现在 SiBCN 陶瓷中的共存。Si₃N₄ 改善了阻抗匹配特性，而 SiC 和相应的异构界面增强了极化损耗能力。此外，石墨条构建了三维导电网络，以提高导电损耗能力。结果，在 15.04 GHz 时最小反射损耗达到 -54.24 dB，有效吸收带宽为 7.48 GHz，厚度为 1.72 mm，覆盖了整个 Ku 波段。SiBCN 陶瓷优异的 EMW 吸收能力可归因于 Si₃N₄ 和 SiC 的协同作用，为制备超薄而强的宽带 EMW 衰减材料提供了新的策略。