中国物理B ›› 2014, Vol. 23 ›› Issue (7): 78101-078101.doi: 10.1088/1674-1056/23/7/078101
• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇 下一篇
沈湘黔, 刘洪波, 王舟, 钱昕晔, 景茂祥, 杨新春
Shen Xiang-Qian (沈湘黔), Liu Hong-Bo (刘洪波), Wang Zhou (王舟), Qian Xin-Ye (钱昕晔), Jing Mao-Xiang (景茂祥), Yang Xin-Chun (杨新春)
摘要: The nanocomposite BaFe12O19/α -Fe and nanocrystalline α -Fe microfibers with diameters of 1-5 μm, high aspect ratios and large specific areas are prepared by the citrate gel transformation and reduction process. The nanocomposite BaFe12O19/α -Fe microfibers show some exchange-coupling interactions largely arising from the magnetization hard (BaFe12O19) and soft (α -Fe) nanoparticles. For the microwave absorptions, the double-layer structures consisting of the nanocomposite BaFe12O19/α -Fe and α -Fe microfibers each exhibit a wide band and strong absorption behavior. When the nanocomposite BaFe12O19/α -Fe microfibers are used as a matching layer of 2.3 mm in thickness and α -Fe microfibers as an absorbing layer of 1.2 mm in thickness, the optimal reflection loss (RL) achieves -47 dB at 15.6 GHz, the absorption bandwidth is about 12.7 GHz ranging from 5.3 to 18 GHz, exceeding -20 dB, which covers 72.5% C-band (4.2-8.2 GHz) and whole X-band (8.2-12.4 GHz) and Ku-band (12.4-18 GHz). The enhanced absorption properties of these double-layer absorbers are mainly ascribed to the improvement in impedance matching ability and microwave multi-reflection largely resulting from the dipolar polarization, interfacial polarization, exchange-coupling interaction, and small size effect.
中图分类号: (Nanocrystalline materials)