Cold Sintering Tunes Nanoparticle Spacing to Unlock Dielectric Resonance for Radar-Absorbing Materials

A new study in Advanced Composites and Hybrid Materials takes a different route: it deliberately induces dielectric resonance, the collective oscillation of local electrons between adjacent but non-contacting particles under an external alternating electric field. By controlling how far apart particles sit, the researchers show they can switch on this resonance-type loss in a family of composite sintered bodies built from molybdenum-based MXene and rare-earth iron oxide nanoparticles. The team, led by Chenghao Jin and Xiaojun Zeng with colleagues including Ruiwen Shu, used a cold press sintering (CSP) technique to anchor rare-earth magnetic nanoparticles onto two-dimensional Mo-MXene, a highly conductive substrate.

Because CSP operates at low temperature rather than the elevated temperatures of conventional sintering, the authors report that it mitigates oxidation of the Mo-MXene nanosheets, preserving their high electrical conductivity so they can supply electrons to the loaded magnetic nanoparticles. Crucially, the process also allows controllable adjustment of the spacing between nanoparticles, which the study identifies as the key parameter for inducing the dielectric response that underpins resonance-type absorption. Experimental measurements and theoretical simulations on three compositions, Mo-MXene combined with CeFeOx, ErFeOx, and GdFeOx, all displayed distinct dielectric resonance characteristics.

According to the authors, this demonstrates that the dielectric resonance-type loss of rare-earth magnetic materials can be modulated through the substrate and the particle arrangement achieved by cold sintering. The composites also maintained excellent magnetic stability across a range of temperatures, an attribute the researchers highlight as important for practical use. Absorption performance was quantified through reflection loss values.

The CeFeOx composite achieved -49.69 dB, the GdFeOx composite reached -40.13 dB, and the ErFeOx composite delivered -33.18 dB. Because all three rare-earth variants showed both the resonance phenomenon and strong absorption, the authors describe the technique as versatile rather than specific to one chemistry, with the resonance behavior and the resulting electromagnetic wave absorption performance observed across the full Mo-MXene/ReFeOx family. To probe practical relevance, the team ran radar cross-section simulations, which indicated that the Mo-MXene/ReFeOx sintered bodies hold potential for radar stealth applications.

The work's broader significance, the researchers argue, is that it breaks through the traditional paradigm of relaxation-loss modulation and offers a new design perspective for dielectric resonance-type electromagnetic wave absorption materials.

Subject of Research: Cold sintering process induces dielectric resonance in Mo-MXene/ReFeOx (Re = Ce, Er, Gd) sintered body for EMW absorption

Article Title: Cold sintering process induces dielectric resonance in Mo-MXene/ReFeOx (Re = Ce, Er, Gd) sintered body for EMW absorption

Article References: Jin, C., Zeng, X., Chen, X., Xie, N., Jiang, Q., & Shu, R. (2026). Cold sintering process induces dielectric resonance in Mo-MXene/ReFeOx (Re = Ce, Er, Gd) sintered body for EMW absorption. Advanced Composites and Hybrid Materials. https://doi.org/10.1007/s42114-026-02135-5

Image Credits: AI Generated

DOI: 10.1007/s42114-026-02135-5

Keywords: Cold, sintering, process, induces, dielectric, resonance, Mo-MXene, ReFeOx, sintered, body, absorption, scientific research