The rational design of electromagnetic wave absorption (EMA) materials featured with broadband and high-efficiency in gigahertz (GHz) is still a great challenge. In this study, we prove fabricating FeNi3 and FeNi3@C core–shell microspheres to solve the challenge. The as-prepared FeNi3 microspheres exhibits extremely broad effective absorption bandwidth (EAB, RL ≥ 10 dB, > 90 % absorbing) of 10.3 GHz (7.7–18.0 GHz) at only 2.0 mm, occupying 64.4 % of the investigated frequency range with a single matching thickness. Such an outstanding EMA performances is credited to strong dielectric loss and magnetic loss. Compared with pristine FeNi3, the delicate design of core–shell structure and tailored synergistic effect of FeNi3 and carbon produce positive reinforcement both in magnetic loss and dielectric loss, endowing FeNi3@C samples with optimized impedance matching and appropriate attenuation ability. As a result, FeNi3@C samples present impressive EMA performances from C to Ku band, especially for FeNi3@C-3, demonstrating its potential of effectively dissipates electromagnetic wave in 6.1–18.0 GHz (RL ≥ 20 dB, > 99 % absorbing) by simply regulating a thickness of 1.5–2.5 mm. FeNi3 and FeNi3@C feature with optional broad bandwidth (completely covering C, X and Ku band), strong absorption, and thin thickness ensure them a superior EMA material.

中文翻译：

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FeNi3 和核壳结构FeNi3@C微球的构建面向宽带电磁波吸收


具有宽带和千兆赫兹 （GHz） 高效率的电磁波吸收 （EMA） 材料的合理设计仍然是一个巨大的挑战。在这项研究中，我们证明了制造 FeNi3 和 FeNi3@C 核壳微球来解决这一挑战。所制备的 FeNi3 微球在仅 2.0 mm 处表现出 10.3 GHz （7.7–18.0 GHz） 的极宽有效吸收带宽（EAB，RL ≥ 10 dB，> 90% 吸收），占据了所研究频率范围的 64.4 %。如此出色的 EMA 性能归功于强介电损耗和磁损耗。与原始的 FeNi3 相比，核壳结构的精细设计以及 FeNi3 和碳的定制协同效应在磁损耗和介电损耗方面均产生正增强，赋予FeNi3@C样品优化的阻抗匹配和适当的衰减能力。因此，FeNi3@C样品在 C 到 Ku 波段，尤其是 FeNi3@C-3 波段表现出令人印象深刻的 EMA 性能，展示了它通过简单地调节 1.5-2.5 mm 的厚度，即可有效消散 6.1–18.0 GHz 电磁波的潜力（RL ≥ 20 dB，> 99 % 吸收）。FeNi3 和 FeNi3@C 具有可选的宽带宽（完全覆盖 C、X 和 Ku 波段）、强吸收和薄厚度特性，使它们成为卓越的 EMA 材料。