Abstract Carbon nanotubes (CNTs)/Indium tin oxide (ITO) composites have been successfully synthesized via coprecipitation and calcination processes. The effects of calcination temperature on the electromagnetic properties of the CNTs/ITO composites were investigated. The real part of the permittivity and the dielectric loss increase with increasing calcination temperature, which can be attributed to the enhanced dielectric relaxation and space charge polarization. The CNTs/ITO composites synthesized at 600 °C can achieve lower reflection loss (RL) value at the thickness of 2–4 mm, while the composites synthesized at 850 °C exhibit broader bandwidth, corresponding to an RL value below −10 dB at a thin coating thickness of 1–1.5 mm. The microwave absorption properties of the CNTs/ITO composites at different frequencies can be tuned by controlling the calcination temperature and the thickness of the absorbing coating. The dielectric loss, quarter-wavelength cancellation, and well-matched characteristic impedance in the air-absorber interface are believed to contribute to the superior microwave absorption performance of the composites. The effects of the secondary phase ITO on the electromagnetic properties of the CNTs/ITO composites were also discussed in this study.

中文翻译：

---

煅烧温度对碳纳米管/氧化铟锡复合材料电磁性能的影响

摘要 碳纳米管 (CNTs)/氧化铟锡 (ITO) 复合材料已通过共沉淀和煅烧工艺成功合成。研究了煅烧温度对CNTs/ITO复合材料电磁性能的影响。介电常数的实部和介电损耗随着煅烧温度的增加而增加，这可归因于增强的介电弛豫和空间电荷极化。在 600 °C 合成的 CNTs/ITO 复合材料可以在 2-4 mm 的厚度下实现较低的反射损耗 (RL) 值，而在 850 °C 合成的复合材料表现出更宽的带宽，对应于低于 -10 dB 的 RL 值1-1.5 毫米的薄涂层厚度。CNTs/ITO复合材料在不同频率下的微波吸收性能可以通过控制煅烧温度和吸收涂层的厚度来调节。空气吸收器界面中的介电损耗、四分之一波长抵消和匹配良好的特性阻抗被认为有助于复合材料的优异微波吸收性能。本研究还讨论了第二相 ITO 对 CNTs/ITO 复合材料的电磁性能的影响。