轻量化多壳层空心结构磁性微纳颗粒的调控与高频电磁特性研究

Carbon nanotubes as light-weight delectric loss absorbing materials have been researched systematically in previous science foundation. Moreover, three SCI articles have been published. In order to acquire light-weight absorber and strong absorbing loss in certain electromagnetic wave band, the magnetic loss absorbing materials are needed to be more light-weight and possess stronger magnetic loss. Our preliminary research shows that the key for light-weight absorber is hollow structure with shell thickness less than skin depth, and the effective way for increasing high-frequency magnetic loss is multi-shell structure which increase absorbing unit with thickness less than skin depth. The project intends to explore the multi-shell hollow structure of magnetic metallic materials in a systematic in-depth study. The number of shell, thickness of shell and particle size will be researched systematically. The interrelated mechanism between the saturation magnetization, coercivity, magnetocrystalline anisotropy field of macro and micro-magnetic properties and the control parameters will be established. The control law of natural resonance, exchange resonance and eddy current loss will be explored. The mechanism of multi-shell hollow structure of magnetic metallic materials as light-weight absorbers will be clarified. The light-weight microwave absorber with excellent microwave absorbing properties will be obtained. The experimental and theoretical basis will be provided for the exploitation and manufacture of light-weight microwave absorber.

青年科学基金工作对碳纳米管作为轻量化介电损耗吸波材料进行了系统研究，已发表相关SCI论文三篇。为了加强在一定电磁波频段工作的吸波体的轻量化和强吸波损耗特征，对磁性损耗吸波材料需要进一步轻量化和增强高频磁性损耗。我们前期的工作表明壳层厚度小于材料趋肤深度的空心结构是吸波体轻量化的关键，而增加趋肤深度以内有效吸波单元的多壳层结构是增强高频磁性损耗的有效途径。本项目拟对多壳层空心结构磁性金属材料进行深入系统研究，调控材料的壳层数量、单层厚度和颗粒尺寸，给出材料的饱和磁化强度、矫顽力和磁晶各向异性场等宏观微观磁性能与各调控参数之间的相互关联机制，探索多壳层空心结构磁性金属材料的自然共振、交换共振和涡流损耗的调控规律，阐明多壳层空心结构磁性金属材料对吸波材料轻量化作用的机理机制，获得具有优良高频电磁波吸收性能的轻量化吸波体，为轻量化吸波体的开发研制提供实验和理论依据。

多壳层空心结构磁性金属微纳颗粒在轻量化吸波体方面具有广阔的应用前景。本项目系统调控多壳层空心结构磁性金属材料，调控材料的颗粒尺寸、壳层厚度和壳层数量，制备得到颗粒尺寸分布为30nm到200nm，壳层厚度为5nm到20nm，壳层数量为1到3层的多壳层空心结构磁性金属材料，并且得到两种颗粒大小为100 nm和颗粒大小为300nm的空心结构磁性金属材料堆叠结构。在双壳层空心结构FeNi合金上观察到由表面各向异性引起的明显的自然共振、交换共振多共振叠加现象。而空心结构FeNi磁性金属材料最优性能为在10mm情况下1GHz处具有-15dB的高频电磁损耗。为了进一步增强磁性金属材料的吸波性能达到阻抗匹配，在保留碳球基础上进行Ni和FeNi的负载，在14.4GHz和15.7GHz均得到强反射吸收损耗。同时制备碳包裹Co3O4/片状碳结构、碳包裹Co3O4@CoO@Co、碳包裹Ni@NiO、Fe@FeO@C、CH3NH3PbI3/单壁碳纳米管、In2S3/单壁碳纳米管和SnSe/多壁碳纳米管多种复合材料，达到阻抗匹配并获得优异的高频电磁波吸收性能。