Abstract The development of stealth technology for military applications and increasing concerns of electromagnetic pollution have garnered interest to design microwave absorbing materials with wide absorption bandwidth and effective absorption properties. Two batches of samples as a potential radar absorbing material were prepared in this study: single-layer and double-layer nanocomposite mixtures of graphite and barium hexaferrite nanoparticles. Characterizations of electromagnetic and microwave absorbing properties were carried out in the frequency range of 8−12 GHz (X-band) and 12−18 GHz (Ku-band). Single-layer samples with thickness of 2 mm showed optimal absorption properties with minimum reflection loss of -20.5 dB at 11.8 GHz for X-band and -20.7 dB at 14.7 GHz for Ku-band, displaying bandwidths of 0.6 GHz for the former and 3.8 GHz for the latter at -10 dB. On the other hand, double-layer samples made of 1 mm thick barium hexaferrite matching layer and 2 mm thick graphite absorbing layer showed optimal absorption properties with minimum reflection loss of -30.0 dB at 9.2 GHz for X-band with narrower bandwidth of 0.6 GHz. The microwave absorption properties of these nanocomposites were attributed to combined effect of dielectric loss from graphite and magnetic loss from ferrite.

中文翻译：

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用于电磁波吸收器应用的单层和双层 BaFe12O19-石墨纳米复合材料的比较研究

摘要 随着军事隐身技术的发展和对电磁污染的日益关注，设计具有宽吸收带宽和有效吸收性能的微波吸收材料引起了人们的兴趣。本研究制备了两批样品作为潜在的雷达吸波材料：石墨和六铁酸钡纳米颗粒的单层和双层纳米复合材料。电磁和微波吸收特性的表征在 8-12 GHz（X 波段）和 12-18 GHz（Ku 波段）的频率范围内进行。厚度为 2 mm 的单层样品显示出最佳吸收特性，X 波段在 11.8 GHz 的最小反射损耗为 -20.5 dB，Ku 波段在 14.7 GHz 的反射损耗为 -20.7 dB，前者和 3 的带宽为 0.6 GHz . 后者为 8 GHz，-10 dB。另一方面，由 1 mm 厚的六铁酸钡匹配层和 2 mm 厚的石墨吸收层制成的双层样品显示出最佳吸收特性，在 9.2 GHz 的 X 波段具有 -30.0 dB 的最小反射损耗，带宽较窄，为 0.6 GHz . 这些纳米复合材料的微波吸收性能归因于石墨的介电损耗和铁氧体的磁损耗的共同作用。