聚吡咯/Ba_(0.9)Nd_(0.1)Fe_(11.5)Cr_(0.5)O_(19)复合物的可控合成及电磁性能

Controlled synthesis of PPy/Ba_(0.9)Nd_(0.1)Fe_(11.5)Cr_(0.5)O_(19) composites and its electrical-magnetic property

用溶胶凝胶法制备了一系列Nd掺杂Ba-铁氧体粉末(Ba1-xNdxFe11.5Cr0.5O19,x=0.00,0.05,0.10,0.15,0.20),选取磁性能相对较好的Ba0.9Nd0.1Fe11.5Cr0.5O19作为磁核,通过原位聚合法制备了不同铁氧体含量的聚吡咯/Ba0.9Nd0.1Fe11.5Cr0.5O19(PPy/BNFCO)复合物.用X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、红外光谱(FTIR)、振动样品磁强计(VSM)、四探针测试仪和矢量网络分析仪等表征了铁氧体粉末和复合物微粒的结构、形貌以及电磁性能.结果表明,Nd的掺杂明显改变了Ba-铁氧体的饱和磁化强度和矫顽力;PPy/BNFCO复合物具有比较明显的核壳结构;复合物的饱和磁化强度随BNFCO含量的增加而增大;电导率则与PPy含量成正比,mpy/mBNFCO=5/1为复合体系渗流阈值;复合物对电磁波的反射损耗和有效带宽是PPy和ZCGFO协同作用的结果,当mpy/mBNFCO为5/1时,PPy/ZCGFO复合物中组分间的协同作用达到最大,其反射峰值和有效带宽分别达到-27.68dB和9.04GHz.PPy/ZCGFO复合物由于良好的微波吸收性能,有望成为电磁波吸收与屏蔽领域的候选材料.

Nd-doped Ba ferrite powders （Ba1-xNdxFe11.5Cr0.5O19,x=0.00,0.05,0.10,0.15,0.20） were obtained by a sol-gel method,and Ba0.9Nd0.1Fe11.5Cr0.5O19 with good magnetic property was chosen as magnetic core to prepare polypyrrole/Ba0.9Nd0.1Fe11.5Cr0.5O19 （（PPy/BNFCO） composites with different ferrite contents by in situ polymerization method. The structures,morphology,electromagnetic property of ferrite powders and composites were characterized by powder X-ray diffractometer （XRD）,transmission electron microscope （TEM）,scanning electron microscope （SEM）,Fourier transform infrared （FTIR） spectra,four-probe instrument,vibrating sample magnetometer （VSM） and vector network analyzer. It was found that Nd contents markedly affected the magnetic properties of Ba1？xNdxFe11.5Cr0.5O19 ferrites. The results also indicated that the PPy/BNFCO composites had obvious core-shell structure. The saturation magnetization of composites increases with increasing of BNFCO content,electrical conductivity is directly proportionalto the PPy content,and the seepage threshold of the composite system locate in mPy/mBNFCO equal to 5/1. The reflection loss of composites and the effective bandwidth for electromagnetic wave were attributed to the synergistic effect between PPy anf BNFCO. The PPy/BNFCO composites with mPy/ mBNFCO = 5/1 have a maximum synergy between its components,show a maximum reflection loss of -27.68 dB at 13.9 GHz and an available bandwidth of 9.04 GHz. It was suggested the PPy/BNFCO composites can be used as a advancing absorption and shielding materials for electromagnetic wave due to their favorable microwave absorption properties.