三元FeCl_3-NiCl_2-GICs的表征及微波吸收性能

Characterization and microwave absorption properties of ternary FeCl_3-NiCl_2-GICs

以天然鳞片石墨为宿主,FeCl3、NiCl2为插层剂,通过熔盐法制备了不同阶结构的三元FeCl3-NiCl2-GICs。采用XRD、SEM、EDS等对GICs的阶结构、表面形貌及成分进行了分析,试样的导电性和微波吸收性能分别由粉末电阻率测定仪和网络矢量分析仪进行测定。结果表明,插层过程中宿主石墨沿c轴方向膨胀并在层面边缘留下侵蚀痕迹,随着阶数的升高边缘侵蚀程度逐渐减弱。不同阶结构的三元FeCl3-NiCl2-GICs中Cl元素在石墨层间均匀分布,而Fe、Ni元素在单个鳞片内则呈不均匀分布,Fe元素的相对百分含量由鳞片边缘向中心呈上升趋势,而Ni元素则完全相反。FeCl3-NiCl2-GICs的电阻率低于宿主石墨,且随着阶数的升高先降低后增大,二阶FeCl3-NiCl2-GICs的导电性最好。FeCl3-NiCl2-GICs具有较好的微波吸收性能,其最大反射损耗量随阶数增大先减小后增大。一阶FeCl-NiCl-GICs反射损耗量最大,在试样厚度为2mm时,其最大反射损耗量为-10.3dB。

Ternary FeCl3-NiCl2-GICs were synthesized by the molten salt method. Natural graphite powder was used as host material and a mixture of FeCl3 and NiCl2 as intercalant. The stage structure, surface topography and components of the GICs were studied by XRD, SEM and EDS. The electrical conductivity and electromagnetic parameters were determined by a transmission reflection network analyzer. Results show that the host graphite is expanded and its edges are eroded badly during intercalation. The degree of erosion levels off with an increase of stage number. For the FeCl3-NiCl2-GICs with different stages, the distribution of Cl is uniform in the graphite layers, while Fe and Ni is non-uniformly distributed in every flake. The percentage of Fe increases from the edge to the center of the FeCl3-NiCl2-GICs flake while Ni shows the opposite behavior. The resistivity of the FeCl3-NiCl2-GICs decreases first, then increases with an increase in stage number. The GICs have relatively good microwave absorption properties and their maximum theoretical reflection loss first decreases, then increases with increasing stage number. Stage-one FeCl3-NiCl2-GICs has the highest reflection loss, which is - 10.3 dB when the thickness is 2 mm.