Abstract Lightweight, strong and broadband microwave absorbents are urgently demanded for practical applications. Exploring magnetic/dielectric composites by anchoring magnetic nanostructures on lightweight dielectric carbon is an effective way, due to their possible good impedance matching condition. Herein, one-dimensional FeCo/C nanofibers are fabricated by electrospinning method and subsequent anoxic annealing treatment, which are used as difunctional magnetic/dielectric microwave absorbents. The nanofibers have a large aspect ratio, in which tiny magnetic FeCo nanocrystals are uniformly decorated in the amorphous dielectric C nanofibers. Benefiting from good impedance matching condition, enhanced microwave attenuation ability and synergistic effect between ferromagnetic FeCo and dielectric C, the FeCo/C nanofibers exhibit boosting microwave absorption performance, which is related to the absorber thickness and filling ratio. The optimal FeCo/C/paraffin composites with 40 wt% of functional fillers show a minimum reflection loss value of −59.9 dB with broad effective absorption bandwidth of 6.0 GHz at 13.2 GHz when the absorber thickness is only 2.6 mm. The FeCo/C nanofibers have a small density of only about 1.1 g/cm3, much smaller than the bulk FeCo (7.4–7.6 g/cm3). Owing to the characteristics of low density, strong absorption and broad effective absorption bandwidth, the FeCo/C nanofibers are promised to be good candidates as microwave absorbents.

中文翻译：

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FeCo纳米晶体支持的碳纳米纤维作为具有宽带微波吸收性能的双功能磁性/介电复合材料

摘要 实际应用迫切需要质轻、强度高、宽带的微波吸收剂。通过将磁性纳米结构锚定在轻质介电碳上来探索磁性/介电复合材料是一种有效的方法，因为它们可能具有良好的阻抗匹配条件。在此，一维 FeCo/C 纳米纤维通过静电纺丝法和随后的缺氧退火处理制成，用作双功能磁性/介电微波吸收剂。纳米纤维具有大的纵横比，其中微小的磁性 FeCo 纳米晶体均匀地装饰在非晶介电 C 纳米纤维中。得益于良好的阻抗匹配条件，增强的微波衰减能力以及铁磁FeCo与电介质C之间的协同作用，FeCo/C 纳米纤维表现出增强的微波吸收性能，这与吸收体厚度和填充率有关。当吸收体厚度仅为 2.6 mm 时，具有 40 wt% 功能性填料的最佳 FeCo/C/石蜡复合材料的最小反射损耗值为 -59.9 dB，在 13.2 GHz 下具有 6.0 GHz 的宽有效吸收带宽。FeCo/C 纳米纤维的密度很小，仅为 1.1 g/cm3，远小于块状 FeCo（7.4-7.6 g/cm3）。FeCo/C纳米纤维具有密度低、吸收强、有效吸收带宽宽的特点，有望成为良好的微波吸收剂候选者。当吸收体厚度仅为 2.6 mm 时，具有 40 wt% 功能性填料的最佳 FeCo/C/石蜡复合材料的最小反射损耗值为 -59.9 dB，在 13.2 GHz 下具有 6.0 GHz 的宽有效吸收带宽。FeCo/C 纳米纤维的密度很小，仅为 1.1 g/cm3，远小于块状 FeCo（7.4-7.6 g/cm3）。FeCo/C纳米纤维具有密度低、吸收强、有效吸收带宽宽的特点，有望成为良好的微波吸收剂候选者。当吸收体厚度仅为 2.6 mm 时，具有 40 wt% 功能性填料的最佳 FeCo/C/石蜡复合材料的最小反射损耗值为 -59.9 dB，在 13.2 GHz 下具有 6.0 GHz 的宽有效吸收带宽。FeCo/C 纳米纤维的密度很小，仅为 1.1 g/cm3，远小于块状 FeCo（7.4-7.6 g/cm3）。FeCo/C纳米纤维具有密度低、吸收强、有效吸收带宽宽的特点，有望成为良好的微波吸收剂候选者。