微/纳米锂锌铁氧体-锌铁氧体空心复相陶瓷微珠的低温自反应淬熄法制备及其电磁损耗性

Micro-/Nano-Spheres of Li-Zn Ferrite-Zinc Ferrite Hollow Multiphase Ceramic Prepared by Low-Temperature Self-Reactive Quenching Technology and Its Electromagnetic Loss Properties

以Li(NO3)-Zn(NO3)2-Fe(NO3)3-CO(NH2)2-酚醛树脂-KH550为反应配系,采用低温自反应淬熄法,制备了微/纳米锂锌铁氧体-锌铁氧体空心复相陶瓷微珠。通过扫描电子显微镜、X射线衍射、透射电子显微镜、综合热分析、高速摄影技术与矢量网络分析仪分别测定了空心复相陶瓷微珠的本征参数与电磁参数,并研究了其形成机理。结果表明:制备的空心复相陶瓷微珠粒径处于几十纳米至5μm之间,成分由尖晶石型的ZnFe2O4和Fe3O4、四方或立方晶系的Fe2O3、菱面体LiFeO2与立方晶系的Li0.5ZnFe2O45种物相组成,表面形貌呈现出纳米等轴晶、多种形貌的纳米析出晶与非晶形态,其中多种形貌的纳米析出晶与非晶组成共晶结构。制备的空心复相陶瓷微珠在低频段具有良好的磁损耗性。"自身细化"、"自身爆裂"、"碰撞"与"边缘效应"是微/纳米锂锌铁氧体-锌铁氧体空心复相陶瓷微珠形成的主要机理。宽的尺寸分布、表面组织结构多样化以及多种成分构成的复相结构是具有良好的电磁损耗性的原因。

The micro-/nano-sized spheres of Li-Zn ferrite-Zinc ferrite hollow multiphase ceramic were prepared with Li(NO3 )-Zn(NO3 )2-Fe(NO3 )3-CO(NH2 )2-phenolic resin-KH550 as raw material by a low-temperature self-reactive quenching meth-od.The intrinsic and electromagnetic parameters were determined by scanning electron microscopy,transmission electron mi-croscopy,X-ray diffraction,differential thermal and thermalgravimetric analysis,high-speed photography and vector network analysis,respectively.The formation mechanism was investigated.The results show that the size range of hollow multiphase ceramic spheres is from several tens of nanometers to 5 microns,and the phase composition consists of spinel ZnFe2 O4 and Fe3 O4 ,tetragonal or cubic Fe2 O3 ,rhombohedral LiFeO2 and cubic Li0.5 ZnFe2 O4 .The spheres are nano-equiaxed precipitated crystallines with the amorphous composition eutectic structure.According to the analysis by electromagnetic tests,the hollow multiphase ceramic spheres have a good magnetic loss in the low frequency.The'self-refinement,“”self-burst',“collision“and“edge effect”are the main mechanisms in the synthesis of micro-/nano-spheres of Li-Zn ferrite-Zinc ferrite hollow multiphase ceramic.The good electromagnetic loss is due to the wider grain size distribution,and the surface structure composed of diverse and complex multi-component phase.