Synthesis of Fe₇S₈/Co₉S₈@CNTs Composites and Their Electromagnetic Wave Absorption Properties

doi:10.12422/j.issn.1006-396X.2026.05.002

Abstract

Abstract:

Carbon nanotubes （CNTs） have excellent dielectric properties,yet single⁃component CNTs easily cause impedance mismatch due to the absence of magnetic loss mechanisms.Compounding them with magnetic materials to achieve dielectric⁃magnetic loss synergy is an effective solution,while the inherent laws of how component ratios systematically affect wave⁃absorbing performance remain poorly explored.In this study,Fe7S8/Co9S8@CNTs composites were prepared via a one⁃step calcination method.By adjusting the ratio of carbon nanotubes to magnetic materials,this study systematically investigated the effects of the two⁃component ratio on the material's phase structure,micro⁃morphology,electromagnetic parameters,and wave⁃absorption performance.Results show Fe7S8/Co9S8@CNTs nanoparticles are uniformly loaded on the inner cavities and outer walls of CNTs. Dielectric loss dominates wave absorption,originating from heterogeneous interfacial polarization,dipole polarization and conductive loss,while magnetic loss is synergistically contributed by natural resonance,exchange resonance and eddy current loss. Optimizing the ratio of carbon nanotubes to magnetic materials achieves the optimal balance between attenuation constant and impedance matching.At a carbon content of 25.27%,Fe7S8/Co9S8@CNTs⁃2 exhibits a minimum reflection loss of -53.3 dB at 2.3 mm thickness,with an effective absorption bandwidth of 4.7 GHz.This study reveals the influence law of component ratio regulation on wave⁃absorbing performance, providing experimental basis and design insights for optimizing carbon⁃based multi⁃component wave⁃absorbing materials.

Key words: Electromagnetic wave absorption, Carbon nanotubes, Component regulation, Impedance matching, Dielectric loss

摘要：

碳纳米管介电性能优异，但单一材料因无磁损耗机制易引发阻抗失配，与磁性材料复合实现介电⁃磁损耗协同，是解决该问题的有效途径，然而目前关于两组分配比对吸波性能内在规律的影响仍缺乏深入探究。采用一步煅烧法制备了Fe₇S₈/Co₉S₈@CNTs复合材料；通过调控碳纳米管与磁性材料的比例，系统研究了两组分比例对材料物相结构、微观形貌、电磁参数及吸波性能的影响。结果表明，Fe₇S₈/Co₉S₈纳米颗粒均匀负载于碳纳米管管腔及管壁；介电损耗在吸波中占主导，源于异质界面极化、偶极极化和导电损耗；磁损耗由自然共振、交换共振和涡流损耗协同贡献；优化碳纳米管与磁性材料的比例可实现衰减常数与阻抗匹配的最佳平衡，当碳纳米管质量分数为25.27%时，Fe₇S₈/Co₉S₈@CNTs⁃2在2.3 mm匹配厚度下的最小反射损耗达-53.3 dB，有效吸收带宽为4.7 GHz。本研究揭示了两组分比例调控对吸波性能的影响规律，为碳基吸波材料性能优化提供了实验依据与设计思路。

关键词: 电磁波吸收, 碳纳米管, 组分调控, 阻抗匹配, 介电损耗

CLC Number:

TB332

Xiaoquan XU, Ning WANG, Mingrui GUO. Synthesis of Fe₇S₈/Co₉S₈@CNTs Composites and Their Electromagnetic Wave Absorption Properties[J]. Journal of Petrochemical Universities, 2026, 39(5): 14-23.

许晓佺, 王宁, 郭铭瑞. Fe₇S₈/Co₉S₈@CNTs复合材料的制备及其电磁波吸收性能研究[J]. 石油化工高等学校学报, 2026, 39(5): 14-23.

Figures/Tables 12

Fig.1 Schematic illustration for the preparation process of Fe?S?/Co?S?@CNTs-X

Fig.2 XRD patterns of Fe?S?/Co?S?@CNTs-X composites

Fig.3 TG curve of Fe?S?/Co?S?@CNTs-X

Fig.4 SEM images and TEM image of Fe?S?/Co?S?@CNTs-2 composite

Fig.5 EDS mappings of Fe?S?/Co?S?@CNTs-2 composite

Fig.6 3D representations of reflection loss for Fe?S?/Co?S?@CNTs-X

Fig.7 Impedance plots of Fe?S?/Co?S?@CNTs-X and optimal reflection loss value and corresponding |Zin/Z0| values

Fig.8 The relationship between the decay constant of Fe?S?/Co?S?@CNTs-X and frequency

Fig.9 Real part, imaginary part of complex permittivity, and dielectric loss tangent of Fe?S?/Co?S?@CNTs-X composites

Fig.10 Real part, imaginary part of complex permeability, and magnetic loss tangent of Fe?S?/Co?S?@CNTs-X composites

Fig.11 Cole-Cole plots of Fe?S?/Co?S?@CNTs-X composites

Fig.12 Eddy current coefficient of Fe?S?/Co?S?@CNTs- X composites

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