School of Materials Science and Engineering, Shaanxi University of Science and Technology, Weiyang, Xi'an, Shaanxi 710021, PR China.
Sci Rep. 2016 Nov 29;6:37892. doi: 10.1038/srep37892.
3D network structure NiFeO was successfully synthesized by a templated salt precipitation method using PMMA colloid crystal as templates. The morphology, phase composition and microwave absorbing properties of as-prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vector network analyzer (VNA), and so on. The results revealed that the 3D network structure was configurated with smooth spherical walls composed of NiFeO nanocrystals and their pore diameters being in the range of 80-250 nm. The microwave absorption properties of the 3D network structure NiFeO were crucially determined by the special structure. The synergy of intrinsic magnetic loss of magnetic NiFeO and the interfacial polarization enhanced by 3D network structure and the interaction of multiple mechanisms endowed the sample with the feature of strong absorption, broad bandwidth and lightweight. There is more than one valley in the reflection loss curves and the maximum reflection loss is 27.5 dB with a bandwidth of 4 GHz. Moreover, the 3D network structure NiFeO show a greater reflection loss with the same thickness comparing to the ordinary NiFeO nanoparticles, which could achieve the feature of lightweight of the microwave absorbing materials.
3D 网络结构的 NiFeO 采用 PMMA 胶体晶体作为模板，通过模板盐沉淀法成功合成。采用扫描电子显微镜（SEM）、X 射线衍射（XRD）、矢量网络分析仪（VNA）等对所制备样品的形貌、相组成和微波吸收性能进行了表征。结果表明，3D 网络结构由 NiFeO 纳米晶组成的光滑球形壁组成，其孔径在 80-250nm 范围内。3D 网络结构赋予了 NiFeO 的特殊结构，对其微波吸收性能起着至关重要的作用。磁性 NiFeO 的本征磁损耗与 3D 网络结构增强的界面极化的协同作用以及多种机制的相互作用赋予了样品强吸收、宽频带和轻重量的特性。在反射损耗曲线上有多个谷，最大反射损耗为 27.5dB，带宽为 4GHz。此外，3D 网络结构的 NiFeO 与普通 NiFeO 纳米粒子相比，在相同厚度下具有更大的反射损耗，这可以实现微波吸收材料的轻重量特性。
