Multi-heterointerface lightweight ceramics achieving temperature-insensitive dielectric properties for high-temperature electromagnetic wave effective absorption

Electromagnetic wave (EMW) absorbing materials capable of efficient performance in high-temperature environments have become a focal point of interest in aerospace, nuclear energy, and civil applications. Unfortunately, current high-temperature EMW absorbing materials not only face challenges related to the chemical stability under extreme environments but also, more critically, encounter significant difficulties in achieving impedance matching across wide-temperature ranges. This challenge primarily arises from the significant variations in temperature-dependent permittivity caused by temperature increases. Despite some studies on high-temperature EMW absorbing materials recognizing that the challenge of achieving wide-temperature-range EMW absorption stems from the temperature sensitivity of permittivity, no further strategies or methods have been proposed based on fundamental mechanisms related to temperature-dependent permittivity to effectively address this issue. Therefore, based on the evolution mechanism of temperature-dependent permittivity, designing materials at the molecular scale to achieve temperature-insensitive permittivity is more instructive and universal for the development of high-temperature EMW absorbing materials.

Recently, a team of material scientists led by Liuying Wang from Rocket Force University of Engineering, China reported a novel molecular-scale strategy for obtaining high-temperature EMW absorbing materials with temperature-insensitive permittivity. This work not only clarifies the significance of the material's temperature-insensitive permittivity for achieving wide-temperature-range EMW absorption performance, but also reveals the potential of this lightweight ceramic as a novel multifunctional thermal protection system.

The team published their work in Journal of Advanced Ceramics on July 12, 2025.

“In this report, we synthesized a novel lightweight high-temperature EMW absorbing ceramic by in situ constructing multi-heterointerface combined with a self-sacrificial template strategy. The formation of a multiphasic heterostructure consisting of β-SiC and β-Si₃N₄ within the amorphous SiOCN matrix significantly enhances charge transfer efficiency at heterointerface, leading to an improved capability for interface dipole polarization in ceramics，” said Liuying Wang, professor at Rocket Force University of Engineering (China), a senior expert whose research interests focus on the field of electromagnetic functional materials.

“The multi-heterointerface lightweight ceramics (MHLCs) demonstrate outstanding temperature-insensitive EMW absorption performance, effectively absorbing EMW within the temperature range of 500 °C to 900 °C at thickness of 3.4 mm and further expanding the temperature range to 25 °C to 900 °C at thickness of 9.41 mm. Therefore, MHLCs show promise as EMW absorbing coatings or structures for applications in high-temperature environments.” said Liuying Wang.

The MHLCs exhibits excellent thermal stability (up to 1000 °C), low density (1.03 g/cm³), low thermal conductivity (0.37 W/(m·K)), and high bending strength (33.55 MPa). “These exceptional physical properties provide the necessary conditions for MHLCs to meet the requirements of various application scenarios,” said Liuying Wang.

Other contributors include Yuchang Qing from the School of Material Science and Engineering at Northwestern Polytechnical University in Xi’an, China; Gu Liu, Weichao Wang, Jie Huang, Qi Gu, Yanyan Lu, and Chaoqun Ge from the Rocket Force University of Engineering, China.

This work was supported by China Postdoctoral Science Foundation (2022M723884) and Special Support Program for High-level Talents of Shaanxi Province (No. 2020-44). The authors would like to thank The Youth Innovation Team of Shaanxi Universities for the guidance on methodology.

About Author

Liuying Wang received the B.Eng., M.Eng., and Ph.D. degrees from the Rocket Force University of Engineering, Xi’an, China, in 1994, 1998, and 2007, respectively. From 2007 to 2009, he was a Postdoctoral Research Fellow in electronic engineering with Xi’an Jiaotong University. He is currently a professor at Rocket Force University of Engineering. He has authored or coauthored more than 70 articles in several journals. His research interests include Electromagnetics, Microwave absorbing devices, Special functional material.

About Journal of Advanced Ceramics

Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen. JAC’s 2024 IF is 16.6, ranking in Top 1 (1/33, Q1) among all journals in “Materials Science, Ceramics” category, and its 2024 CiteScore is 25.9 (5/130) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508