Dual rare-earth modification and interface engineering in SiC-based heterostructures for multi-frequency electromagnetic wave absorption

Abstract The escalating complexity of the electromagnetic environment calls for advanced electromagnetic wave (EMW) absorption materials capable of efficient multi-frequency attenuation. Silicon carbide (SiC) is a promising dielectric candidate but is hindered by intrinsic impedance mismatch and limited polarization loss. Herein, we report a novel ternary heterostructure absorber consisting of SiC nanowires synergistically coupled with dual rare-earth silicides (Ce5Si4 and Pr5Si4) fabricated via a combined magnesiothermic and carbothermal reduction process using an MFI-type zeolite precursor. This unique architecture creates an intricate porous network featuring abundant multiple heterogeneous interfaces (SiC/Ce5Si4, SiC/Pr5Si4, and Ce5Si4/Pr5Si4). The simultaneous incorporation of Ce and Pr optimizes the complex permittivity for impedance matching and induces intense multi-interfacial polarization relaxation. Consequently, the designed composite achieves efficient and strong EMW absorption performance in the C-band (4.30 GHz), X-band (8.24 GHz), and Ku-band (16.51 GHz), demonstrating remarkable multi-frequency point absorption performance. Radar cross-section (RCS) simulations further demonstrate its significant stealth capability, highlighting the potential of dual rare-earth synergistic engineering. This work provides a pioneering strategy for designing high-performance, multi-frequency SiC-based absorbers through the construction of ternary rare-earth silicide heterostructures.