聚合质量比对Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19／PAn复合体系微波吸收性能的影响

用原位聚合法制备了Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19铁氧体／聚苯胺（PAn）复合材料。采用X射线衍射（XRD）、扫描电子显微镜（SEM）对样品的结构、微观表面形貌和粒子大小进行了表征，用微波矢量网络分析仪测量样品在2～12．4GHZ频率范围内复介电常数和复磁导率，根据测量数据计算微波反射率R与频率f的关系。研究结果表明：PAn包覆于掺杂锶铁氧体表面，PAn／Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19复合材料具有良好的吸波性能，随着掺杂锶铁氧体含量的增加，微波吸收匹配厚度和吸收带宽发生变化：当Sr0．7La0．15Ce0．15Fe11.7Zn0．3O19聚合质量比为40％时，最佳匹配厚度为2．6mm，吸收峰值接近-40dB，峰值频率高于12．4GHz，大于10dB吸收带宽预计达到55GHz。

Effects of Sr_(0.7)La_(0.15)Ce_(0.15)Fe_(11.7)Zn_(0.3)O_(19)Content on Microwave Absorption Properties of Conductive Polyaniline

PAn/ Sr_(0.7)La_(0.15)Ce_(0.15)Fe_(11.7)Zn_(0.3)O_(19) composites were prepared by polymerization in situ. X-ray diffraction(XRD) and scanning electron microscopy(SEM) were employed to characterize the structure,surface morphology and particle size of the samples. The complex permittivity and complex permeability of the samples were measured by microwave vector network analyzer in the frequency range of 2 - 12.4 GHz. The relations between the reflection loss and frequency were calculated from the measured data. The resuhs showed that the doped stron-tium ferrite powder were successfully coated with PAn and PAn/ Sr_(0.7)La_(0.15)Ce_(0.15)Fe_(11.7)Zn_(0.3)O_(19) composites have excellent microwave ab-sorption properties so that the absorptive match thickness and absorptive bandwidth changed with the content of doped stronitium ferrite pow-der. When Sr_(0.7)La_(0.15)Ce_(0.15)Fe_(11.7)Zn_(0.3)O_(19) mass ratio is 40% ,the best match thickness was 2.6 mm,microwave absorbing peak was near -40 dB at a frequency higher than 12.4 GHz and the absorption bandwidth greater than 10 dB was expected to reach 5.5 GHz.