Polymer-derived nanocrystalline/amorphous TiC/SiC heterostructures for enhanced electromagnetic wave absorption

The escalating electromagnetic pollution in modern electronic and communication systems has driven increasing demand for high-performance electromagnetic wave (EMW) absorbing materials. Polymer-derived SiC-based ceramics have attracted great attention for EMW absorption owing to their tunable phase compositions and adjustable conductivity. However, their practical performance is often constrained by poor impedance matching and insufficient dielectric polarization and attenuation mechanisms. In the present work, ceramic heterostructures comprising MXene-derived TiC nanocrystals embedded in a predominantly amorphous Si-containing matrix were synthesized using polycarbosilane and Ti 3 C 2 T x MXene as precursors. Microstructural and phase analyses reveal that most of the introduced MXene is converted in situ into nanocrystalline TiC, while the PCS-derived Si-containing matrix remains predominantly amorphous. The resulting multiphase ceramics exhibit abundant heterointerfaces and defect structures, which synergistically enhance interfacial polarization and dielectric loss while improving impedance matching. Therefore, the obtained multiphase samples achieve a minimum reflection loss of − 45.7 dB at 1.4 mm thickness and a broad 6.24 GHz bandwidth at a matching thickness of 1.7 mm. These results demonstrate that interface engineering via MXene incorporation is an effective strategy for tailoring microstructure and optimizing EMW absorption performance in polymer-derived ceramic systems.