Nb₂O₅/α-Fe₂O₃heterostructures as next-generation electromagnetic shields with ultra-low reflectivity: Toward stealth technology

Electromagnetic interference (EMI) is highly undesirable in modern electronic and defense fields; hence, it compels the development of advanced radar-absorbing materials (RAMs) featuring high total shielding effectiveness (SE_T) with low microwave reflection. In this paper, a novel Nb₂O₅/α-Fe₂O₃heterostructure nanocomposite (NF) was prepared by a dual hydrothermal method. Nb₂O₅nanoparticles and α-Fe₂O₃nanorods were prepared separately and then assembled into heterostructures, which were introduced into the silicone elastomer matrix to fabricate EMI shielding composite specimens. The structural, morphological, and thermal characterizations confirmed the realization of phase-pure and well-interconnected nanocomposites with enhanced crystallinity, interfacial interaction, and qualitative thermal stability of the elaborated materials up to 1200 K. The synthesized NF composite exhibited a high value of around 20 dB SE_T, dominated by an absorption component (SE_A ≈ 19.5 dB) with only about 0.5 dB contribution of the reflection component (SE_R). Therefore, this rise in EMI shielding is caused by balanced dielectric and magnetic loss, interfacial polarization, and a strong conductive network forming in the composite. Such heterostructure nanocomposites could be potential high-performance materials for industrial and defense-oriented EMI shielding applications due to superior SE_T, simple structure, and multifunctionality.