Anisotropic Interfaces Support the Confined Growth of Magnetic Nanometer‐Sized Heterostructures for Electromagnetic Wave Absorption

Abstract

The fabrication of nanometer‐sized magnetic heterostructures with controlled magnetic components and specific interfaces holds great significance in the field of electromagnetic (EM) wave absorption. However, the process of achieving these structures still poses significant challenges. Here, abundant magnetic heterostructures are successfully fabricated by utilizing the surface energy anisotropy differences of the nonasymmetric hammer‐shaped interface to support the nucleation and growth of magnetic heterostructure components while effectively inhibiting their aggregation. Through a confined growth strategy via in situ growth of FeOOH and sequentially precise thermal treatments, dispersion of the heterostructures is achieved at the nanometer scale, while also observing a high degree of chemical stability due to occurrence of a charge‐compensation effect at the interface. Consequently, a series of magnetic heterostructures are obtained via phase translations of FeOOH precursors. The nanometer‐sized heterostructures demonstrate multilevel interfacial polarization effects. Furthermore, the hierarchical core–shell structure of the heterostructures promotes anisotropic polarization absorption. As a result, the multiple interfaces and nanometer‐sized Fe/Fe3O4@SiO2@Fe‐2 heterostructures demonstrate improved EM wave attenuation performance. Remarkably, they achieve an absorption bandwidth of 9 GHz at a thickness of 1.8 mm. A novel avenue is introduced here for investigating the intricate relationship between structure and properties in magnetic heterostructures.

Novel Local-Chiral Metamaterial: Effective Modulation of Amplitude & Phase for Wideband Polarization-Insensitive Absorption

“…As a significant subdivision of the metamaterial field, metamaterial absorbers (MMAs) can convert the EM wave energy at a specific frequency into heat or other forms of energy through EM resonance. Compared to traditional absorbers composed of dielectric − or magnetic − loss materials, the qualities of MMAs such as low profile, strong absorption, and on-demand design make them a promising option in applications of stealth technology, EM wave sensing, and energy harvesting. ,− …”

Structural Engineering of Hierarchical Magnetic/Carbon Nanocomposites via In Situ Growth for High-Efficient Electromagnetic Wave Absorption

“…Materials engineered for electromagnetic wave (EMW) absorption have garnered significant interest due to their diverse applications in wireless communication, information processing, and radar stealth technology [1][2][3][4]. Moreover, these materials play a crucial role in addressing electromagnetic radiation pollution, which poses threats to human health and disrupts the operation of precision electronic equipment [5][6][7]. However, traditional EMW absorption materials encounter challenges in meeting the evolving needs of the high-tech era.…”