According to the escalating concern regarding the health hazards associated with electromagnetic radiation, the significance of absorbing materials underscores which could mitigate the healthy risks. While magnetic materials offer excellent absorption performance, their high density poses challenges to achieving optimal absorption efficiency. Conversely, carbon-based materials are known for their lightweight and versatile but face impedance matching issues. To address these obstacles, carbon/magnetic composite materials have been explored. However, their absorption performance has not fully met requirements due to weaker magnetic properties and increased density. Herein, we synthesized a porous carbon material embedded with magnetic FeNi/NiFeO and dielectric SiO nanoparticles (FeNi-NiFeO-SiO@PC) using carbonthermal method. By adjusting the ratio of polyvinylpyrrolidone to nitrates, the electromagnetic wave (EMW) absorption performance is adjusted. The FeNi-NiFeO-SiO@PC composites display remarkable EMW absorption properties, achieving a minimum reflection loss of −69.9 dB at a thin thickness of 1.495 mm and a maximum effective absorption bandwidth of 5.68 GHz, covering the range from 12.32 to 18.0 GHz at a thickness of 1.92 mm. This outstanding performance can be attributed to the favorable impedance matching and the three-dimensional porous structure, which facilitates a 3D transmission network for multiple reflections. Additionally, the presence of FeNi, NiFeO, and SiO nanoparticles enhances magnetic loss, conductive loss, interface polarization, and dipolar polarization, leading to excellent ab. Hence, this work offers insights into the composition design of high-performance absorbing materials.

中文翻译：

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负载磁性 FeNi/NiFe2O4 和介电 SiO2 纳米颗粒的多孔碳复合纳米片可调节微波吸收


随着人们对电磁辐射相关健康危害的日益关注，吸波材料的重要性凸显了它可以减轻健康风险。虽然磁性材料具有出色的吸收性能，但其高密度对实现最佳吸收效率提出了挑战。相反，碳基材料以其轻质和多功能而闻名，但面临着阻抗匹配问题。为了解决这些障碍，人们对碳/磁性复合材料进行了探索。然而，由于磁性能较弱和密度增加，它们的吸波性能尚未完全满足要求。在此，我们采用碳热法合成了嵌入磁性 FeNi/NiFeO 和介电 SiO 纳米颗粒的多孔碳材料（FeNi-NiFeO-SiO@PC）。通过调节聚乙烯吡咯烷酮与硝酸盐的比例，可以调节电磁波（EMW）吸收性能。 FeNi-NiFeO-SiO@PC复合材料表现出卓越的电磁波吸收性能，在1.495mm的薄厚度下实现了-69.9dB的最小反射损耗，最大有效吸收带宽为5.68GHz，覆盖了12.32至18.0GHz的范围。厚度1.92毫米。这种出色的性能可归因于良好的阻抗匹配和三维多孔结构，有利于多重反射的3D传输网络。此外，FeNi、NiFeO 和 SiO 纳米颗粒的存在增强了磁损耗、传导损耗、界面极化和偶极极化，从而产生优异的 ab。因此，这项工作为高性能吸波材料的成分设计提供了见解。