Electromagnetic pollution is becoming an increasingly difficult problem to ignore. As wireless communication networks, radar systems, satellites, electric vehicles, wearable electronics, and densely packed computing devices continue to expand, the surrounding environment is filled with electromagnetic radiation across a wide range of frequencies. Much of this radiation is harmless at ordinary exposure levels, but unwanted electromagnetic interference can disrupt sensitive equipment, reduce signal reliability, compromise electronic security, and interfere with the operation of complex technologies. Scientists are therefore searching for materials that can absorb electromagnetic waves before they are reflected or transmitted into surrounding systems. A new study published in Advanced Composites and Hybrid Materials reports a promising strategy based on a carefully engineered ceramic architecture built from titanium carbide nanocrystals and an amorphous silicon-containing matrix.
The material was created using polycarbosilane, a polymer widely used as a precursor for silicon carbide ceramics, together with Ti₃C₂Tₓ MXene. MXenes are two-dimensional transition-metal carbides and nitrides known for their high electrical conductivity, layered structure, and rich surface chemistry. These characteristics have made them attractive for energy storage, sensing, catalysis, shielding, and electromagnetic absorption. However, their conductivity can also become a disadvantage when the material reflects too much incoming radiation instead of absorbing it. A strong electromagnetic absorber must achieve a delicate balance: it needs enough electrical activity to dissipate electromagnetic energy, but not so much that waves are rejected at the material’s surface. The Zhengzhou University-led research team addressed this challenge by converting the MXene precursor into nanoscale TiC within a predominantly amorphous silicon-containing ceramic.
The resulting structure is not a conventional, single-phase ceramic. Instead, it is a heterostructure in which nanocrystalline titanium carbide domains are distributed through a largely amorphous matrix derived from polycarbosilane. During thermal conversion, most of the introduced MXene is transformed in situ into TiC nanocrystals, while the polymer-derived silicon-containing phase retains a disordered, non-crystalline character. This combination is important because crystalline and amorphous regions interact differently with electromagnetic fields. The interfaces between them create locations where charge carriers can accumulate, especially when the electric field oscillates rapidly. Such charge accumulation produces interfacial polarization, a mechanism that converts electromagnetic energy into heat through delayed movement of charges across boundaries.
The researchers describe these interfaces as one of the central features responsible for the material’s performance. At the nanoscale, the boundary between TiC crystals and the amorphous matrix contains chemical irregularities, structural disorder, and defects. These imperfections can act as traps or barriers for mobile electrons, preventing them from moving freely through the entire material. When an electromagnetic wave reaches the heterostructure, the alternating field drives charges back and forth. Instead of flowing without resistance, the charges repeatedly encounter interfaces and defect sites. Their interrupted movement generates dielectric loss, weakening the electromagnetic wave as energy is dissipated inside the ceramic. The effect is enhanced by the large number of boundaries created when nanocrystals are embedded throughout the matrix.
Electromagnetic absorption depends on more than simply increasing electrical conductivity. A material must also possess suitable impedance matching with the surrounding air. Impedance describes how a material responds to an electromagnetic field, and a severe mismatch causes most of the incident energy to bounce away from the surface. In an absorber, the incoming wave must be able to enter the material before it can be attenuated. The TiC/amorphous Si-containing design helps moderate this balance. The ceramic matrix limits the excessive conductivity that could otherwise produce strong reflection, while the TiC nanocrystals provide conductive pathways and polarization centers. This combination allows electromagnetic energy to penetrate the composite and then encounter multiple mechanisms capable of converting it into heat.
The study reports a minimum reflection loss of −45.7 decibels at a thickness of 1.4 millimeters. In practical terms, this value indicates that only a very small fraction of the incident electromagnetic energy is reflected back under the reported testing conditions, while the rest is absorbed or otherwise attenuated. The material also achieved an effective absorption bandwidth of 6.24 gigahertz at a matching thickness of 1.7 millimeters. A broad bandwidth is particularly valuable because modern devices do not operate at a single universal frequency. Communication systems, radar technologies, navigation equipment, and electronic platforms occupy different portions of the spectrum. An absorber that performs strongly across several gigahertz is more useful than one that reaches an impressive peak within a very narrow frequency window.
The reported thicknesses are also significant. Electromagnetic absorbers often become less attractive for real-world applications when they require bulky layers to achieve effective attenuation. Reducing the thickness while maintaining strong absorption can support lighter coatings, compact shielding components, and more flexible integration into electronic assemblies. The TiC/SiC-related heterostructure reaches its strongest reported reflection-loss value at only 1.4 millimeters, while its broad absorption response appears at 1.7 millimeters. These dimensions suggest that the material could be relevant to applications where space, weight, and electromagnetic compatibility must be considered together. The study does not claim that the ceramic is ready for immediate commercial deployment, but its combination of nanoscale architecture, high attenuation, and relatively low matching thickness makes it a compelling platform for further development.
The work also highlights why polymer-derived ceramics are attracting attention in advanced materials research. Unlike conventional ceramic processing, polymer-derived ceramic routes begin with molecular precursors that can be shaped, blended, coated, or infiltrated before conversion at high temperature. During pyrolysis, the precursor decomposes and reorganizes into a ceramic network, allowing scientists to tune composition, porosity, crystallinity, and electrical properties. Polycarbosilane is especially useful because it can form silicon carbide-related phases while accommodating additional elements or nanomaterials. By introducing MXene before conversion, the researchers effectively used the polymer precursor as a host and reaction environment for generating a new multiphase structure. This approach may offer greater control over interfaces than simply mixing pre-existing ceramic powders.
The findings are likely to attract attention beyond electromagnetic shielding because they demonstrate a broader principle in materials design: disorder can be engineered rather than avoided. In many ceramic systems, amorphous regions, defects, and imperfect boundaries are regarded as flaws that reduce structural uniformity. For electromagnetic absorption, however, these features can become functional assets. The amorphous phase supplies disorder and resistance to charge motion, while the TiC nanocrystals contribute conductivity and additional polarization sites. Their intimate contact creates a network in which electromagnetic energy is repeatedly scattered, polarized, and dissipated. The researchers therefore present MXene incorporation not merely as a way to add a conductive ingredient, but as an interface-engineering strategy capable of reshaping the entire absorption mechanism of a polymer-derived ceramic.
Future work will need to determine how the material behaves under conditions closer to practical operation, including high temperatures, mechanical stress, prolonged electromagnetic exposure, and environmental aging. Researchers may also explore how the amount of MXene, the size of the TiC nanocrystals, the chemistry of the amorphous matrix, and the pyrolysis conditions influence impedance matching and absorption bandwidth. Scaling the synthesis from laboratory samples to large-area coatings or complex three-dimensional components will be another important challenge. Even so, the study offers a clear and potentially versatile route toward thinner, broadband electromagnetic absorbers. By transforming a two-dimensional MXene precursor into TiC nanocrystals embedded in an amorphous silicon-containing ceramic, the team has created a structure in which interfaces, defects, and controlled conductivity work together rather than compete. The result is a striking example of how nanoscale architecture can turn a complex materials problem into a powerful new opportunity for electromagnetic protection.
Subject of Research: Polymer-derived TiC/amorphous SiC-based ceramic heterostructures for electromagnetic wave absorption
Article Title: Polymer-derived nanocrystalline/amorphous TiC/SiC heterostructures for enhanced electromagnetic wave absorption
Article References: Zu, D., Huang, G., Li, W. et al. “Polymer-derived nanocrystalline/amorphous TiC/SiC heterostructures for enhanced electromagnetic wave absorption.” Advanced Composites and Hybrid Materials (2026).
Image Credits: AI Generated
DOI: https://doi.org/10.1007/s42114-026-02030-z
Keywords: Polycarbosilane; MXene; TiC nanocrystals; SiC; heterostructures; polymer-derived ceramics; electromagnetic wave absorption; dielectric loss; interfacial polarization
