Abstract A new multifunctional microwave absorbing material is designed. Two types of ferrites were synthesized, namely soft NiCoTi ferrite and hard SrCoTi ferrites, by sol-gel auto combustion method. Then, the ferrites along with an appropriate quantity of micro-copper particles were coated by polypyrrole using in situ chemical polymerization of pyrrole. The resulted material was hosted into a polyurethane matrix to prepare a microwave absorbing paint. The accumulative roles of the different components of the microwave absorber were investigated. The permittivity and permeability were recorded in the X-band and the reflection loss of the material at different thicknesses was estimated. The structure of the prepared microwave absorbing material was investigated using XRD and FTIR spectroscopy. VSM was used to record the samples’ magnetic hysteresis loops. The morphology of the absorber was studied using SEM. The new prepared microwave absorbing composite material was compared to a simple mixture of its components and the importance effect of the interfacial polarization was highlighted. The microwave absorption properties were measured in the X-band range as a function of absorber thickness, Ferrites/PPY ratio and copper percentage. By changing Ferrites/PPY ratio the microwave absorption performance was tuned. The optimal copper percentage in the composite was optimized and it was found that 10 %w/w of copper widens the -10 dB bandwidth to 3 GHz and enhances the maximum reflection loss to -24 dB.

中文翻译：

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使用铜颗粒和聚吡咯涂层调整 X 波段微波吸收涂料的阻抗匹配特性

摘要 设计了一种新型多功能吸波材料。采用溶胶-凝胶自燃法合成了软质NiCoTi铁氧体和硬质SrCoTi铁氧体两种铁氧体。然后，使用吡咯的原位化学聚合，将铁氧体和适量的微铜颗粒用聚吡咯包覆。将所得材料置于聚氨酯基质中以制备微波吸收涂料。研究了微波吸收剂不同组分的累积作用。在 X 波段记录介电常数和磁导率，并估算不同厚度下材料的反射损耗。使用XRD和FTIR光谱研究了制备的吸波材料的结构。VSM 用于记录样品的磁滞回线。使用SEM研究吸收体的形态。将新制备的吸波复合材料与其组分的简单混合物进行了比较，并强调了界面极化的重要性。在 X 波段范围内测量微波吸收特性，作为吸收体厚度、铁氧体/PPY 比和铜百分比的函数。通过改变铁氧体/PPY 比率，可以调整微波吸收性能。优化了复合材料中的最佳铜百分比，发现 10%w/w 的铜将 -10 dB 带宽扩大到 3 GHz，并将最大反射损耗提高到 -24 dB。将新制备的吸波复合材料与其组分的简单混合物进行了比较，并强调了界面极化的重要性。在 X 波段范围内测量微波吸收特性，作为吸收体厚度、铁氧体/PPY 比和铜百分比的函数。通过改变铁氧体/PPY 比率，可以调整微波吸收性能。优化了复合材料中的最佳铜百分比，发现 10%w/w 的铜将 -10 dB 带宽扩大到 3 GHz，并将最大反射损耗提高到 -24 dB。将新制备的吸波复合材料与其组分的简单混合物进行了比较，并强调了界面极化的重要性。作为吸收体厚度、铁氧体/PPY 比率和铜百分比的函数，在 X 波段范围内测量微波吸收特性。通过改变铁氧体/PPY 比率，可以调整微波吸收性能。优化了复合材料中的最佳铜百分比，发现 10%w/w 的铜将 -10 dB 带宽扩大到 3 GHz，并将最大反射损耗提高到 -24 dB。通过改变铁氧体/PPY 比率，可以调整微波吸收性能。优化了复合材料中的最佳铜百分比，发现 10%w/w 的铜将 -10 dB 带宽扩大到 3 GHz，并将最大反射损耗提高到 -24 dB。通过改变铁氧体/PPY 比率，可以调整微波吸收性能。优化了复合材料中的最佳铜百分比，发现 10%w/w 的铜将 -10 dB 带宽扩大到 3 GHz，并将最大反射损耗提高到 -24 dB。