Abstract A facile and scalable metal-organic chemical vapor deposition method is proposed for the fabrication of ultra-small FeNi-C core-shell nanoparticles. As-synthesized nanoparticles are composed of ultra-small FeNi nanocores of an average diameter of ∼ 6.2 nm and thin shells of 1–3 nm in thickness, which are stable in air atmosphere up to 210 °C. The ratio of Fe/Ni in the nanocores was tuned by varying the reaction temperature, suggesting a simple route to tailor the magnetic and microwave absorption properties of the synthesised nanostructures. These core-shell nanoparticles with a filler loading of 16.7% in paraffin wax exhibited a low minimum reflection loss ( R L m i n ) of -63.7 dB, together with a great effective bandwidth ( B W e f f ) of 6.5 GHz at a thickness of 2.2 mm, attributing to their ultra-small size and unique magnetic-dielectric core-shell nanostructure. Such core-shell nanoparticles should be a strong candidate as a light-weighted absorber with tunable microwave absorption performance.

中文翻译：

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Fe/Ni比对超小FeNi-C核壳纳米粒子微波吸收性能的简易合成及影响

摘要 提出了一种简便且可扩展的金属有机化学气相沉积方法，用于制备超小型 FeNi-C 核壳纳米粒子。合成后的纳米粒子由平均直径约 6.2 nm 的超小 FeNi 纳米核和厚度为 1-3 nm 的薄壳组成，在高达 210 °C 的空气中稳定。通过改变反应温度来调节纳米核中 Fe/Ni 的比例，这表明了一种调整合成纳米结构的磁性和微波吸收特性的简单途径。这些在石蜡中填充量为 16.7% 的核壳纳米粒子表现出 -63.7 dB 的低最小反射损耗 (RL min )，以及 6.5 GHz 的有效带宽 (BW eff)，厚度为 2.2 mm，归因于它们的超小尺寸和独特的磁介电核壳纳米结构。这种核壳纳米粒子应该是具有可调微波吸收性能的轻质吸收剂的有力候选者。