Core/shell structured Ni/Fe3O4 composites with grain sizes of 200–800 nm were synthesized by using a hydrothermal method. The phase structure, morphology, magnetic and electromagnetic absorption properties of the as-prepared samples were characterized by various analysis techniques. Experimental results revealed that spinel Fe3O4 was in situ deposition on the surface of Ni spheres through electrostatic interactions. Moreover, the Ni/Fe3O4 mass ratios had a significant influence on the electromagnetic absorption performances. When the mass ratio of Ni/Fe3O4 was 1:1, the composites reached an outstanding reflection loss (RL) of [Formula: see text]48.06[Formula: see text]dB at 12.96[Formula: see text]GHz with a thin thickness of 1.8[Formula: see text]mm. Meanwhile, the effective absorption bandwidth was 5.36[Formula: see text]GHz (10.72–16.08[Formula: see text]GHz), covering the X and Ku bands. The enhanced electromagnetic absorption performance of core/shell structured Ni/Fe3O4 composites as compared to pure Ni, may be attributed to the multiple interfacial polarization, magnetic exchange coupling resonance and optimal impedance matching. Consequently, core/shell structured Ni/Fe3O4 composites would be promising candidates for a wider range of electromagnetic absorption applications.

中文翻译：

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具有增强电磁吸收性能的核/壳结构 Ni/Fe3O4 复合材料

核/壳结构 Ni/Fe3○4采用水热法合成了粒径为 200-800 nm 的复合材料。通过各种分析技术对所制备样品的相结构、形貌、磁性和电磁吸收特性进行了表征。实验结果表明尖晶石Fe3○4是通过静电相互作用在镍球表面原位沉积。此外，Ni/Fe3○4质量比对电磁吸收性能有显着影响。当 Ni/Fe 的质量比3○4为 1:1，复合材料在 12.96[公式：见文本]GHz 处达到了 [公式：见文本]48.06[公式：见文本]d​​B 的出色反射损耗 (RL)，厚度为 1.8 [公式：见文本]毫米。同时，有效吸收带宽为5.36[公式：见文]GHz（10.72-16.08[公式：见文]GHz），覆盖X波段和Ku波段。核/壳结构Ni/Fe增强的电磁吸收性能3○4与纯镍相比，复合材料可能归因于多界面极化、磁交换耦合共振和最佳阻抗匹配。因此，核/壳结构的 Ni/Fe3○4复合材料将是更广泛的电磁吸收应用的有希望的候选者。