中国物理B ›› 2013, Vol. 22 ›› Issue (5): 58101-058101.doi: 10.1088/1674-1056/22/5/058101
• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇 下一篇
杨新春a, 刘瑞江b, 沈湘黔a, 宋福展a, 景茂祥a, 孟献丰a
Yang Xin-Chun (杨新春)a, Liu Rui-Jiang (刘瑞江)b, Shen Xiang-Qian (沈湘黔)a, Song Fu-Zhan (宋福展)a, Jing Mao-Xiang (景茂祥)a, Meng Xian-Feng (孟献丰)a
摘要: Nanocomposite BaFe12O19/α-Fe microfibers with diameters of about 1-5 μm are prepared by the organic gel-thermal selective reduction process. The binary phase of BaFe12O19 and α-Fe is formed after reduction of the precursor BaFe12O19/α-Fe2O3microfibers at 350 ℃ for 1 h. These nanocomposite microfibers are fabricated from α-Fe (16-22 nm in diameter) and BaFe12O19 particles (36-42 nm in diameter) and basically exhibit a single-phase-like magnetization behaviour, with a high saturation magnetization and coercive force arising from the exchange-coupling interactions of soft α-Fe and hard BaFe12O19. The microwave absorption characteristics in a 2-18 GHz frequency range of the nanocomposite BaFe12O19/α-Fe microfibers are mainly influenced by their mass ratio of α-Fe/BaFe12O19 and specimen thickness. It is found that the nanocomposite BaFe12O19/α-Fe microfibers with a mass ratio of 1:6 and specimen thickness of 2.5 mm show an optimal reflection loss (RL) of -29.7 dB at 13.5 GHz and the bandwidth with RL exceeding -10 dB covers the whole Ku-band (12.4-18.0 GHz). This enhancement of microwave absorption can be attributed to the heterotructure of soft, nano, conducting α-Fe particles embedded in hard, nano, semiconducting barium ferrite, which improves the dipolar polarization, interfacial polarization, exchange-coupling interaction, and anisotropic energy in the nanocomposite BaFe12O19/α-Fe microfibers.
中图分类号: (New materials: theory, design, and fabrication)