Yang Xinchun, Jing Maoxiang, Shen Xiangqian, Meng Xianfeng, Dong Mingdong, Huang Daqing, Wang Yingde
J Nanosci Nanotechnol. 2014 Mar;14(3):2419-24. doi: 10.1166/jnn.2014.8479.
The microwave absorption properties of sandwich structural absorbers based on the nanocrystalline strontium ferrite (SrFe12O19), NiZn ferrite (Ni0.5Zn0.5Fe2O4) and alpha-iron (alpha-Fe) hollow microfibers with diameters of 1-3 microm have been investigated in the frequency range of 2-18 GHz. The sandwich absorbers composed of nanocrystalline ferrite hollow microfibers as the outer or inner layer, and the nanocrystalline alpha-Fe hollow microfibers as the interlayer, have strong microwave absorption with a broad band and thin thickness. Their microwave absorption properties in 2-18 GHz are mainly influenced by the arrangement, each layer thickness and total thickness. It finds that the sandwich absorber with 1.6 mm thick SrFe12O19 microfibers as the outer layer, 0.2 mm thick alpha-Fe microfibers as the interlayer and 0.2 mm thick Ni0.5Zn0.5Fe2O4 microfibers as the inner layer, exhibits an optimal reflection loss (RL) value of -120.1 dB at 13.2 GHz and the bandwidth with RL exceeding -10 dB covers 83% of X-band (8.2-12.4 GHz) and the whole K(u)-band (12.4-18 GHz). This enhancement microwave absorption can be attributed to the unique coupling of the nanocrystalline ferrite and alpha-Fe hollow microfibers arising from the shape anisotropy, interface and small size effects.
研究了基于直径为1 - 3微米的纳米晶锶铁氧体（SrFe12O19）、镍锌铁氧体（Ni0.5Zn0.5Fe2O4）和α - 铁（α - Fe）空心微纤维的三明治结构吸波材料在2 - 18 GHz频率范围内的微波吸收特性。由纳米晶铁氧体空心微纤维作为外层或内层，以及纳米晶α - Fe空心微纤维作为中间层组成的三明治吸波材料，具有宽带、薄厚度的强微波吸收特性。它们在2 - 18 GHz的微波吸收特性主要受排列方式、各层厚度和总厚度的影响。研究发现，以1.6毫米厚的SrFe12O19微纤维为外层、0.2毫米厚的α - Fe微纤维为中间层、0.2毫米厚的Ni0.5Zn0.5Fe2O4微纤维为内层的三明治吸波材料，在13.2 GHz时表现出最佳反射损耗（RL）值为 - 120.1 dB，RL超过 - 10 dB的带宽覆盖了X波段（8.2 - 12.4 GHz）的83%以及整个K（u）波段（12.4 - 18 GHz）。这种增强的微波吸收可归因于纳米晶铁氧体和α - Fe空心微纤维由于形状各向异性、界面和小尺寸效应而产生的独特耦合。
