FeNi/Ba0.6Sr0.4TiO3核壳纳米结构的制备及低频吸波机理研究

Preparation and Low Frequency Absorbing Properties of FeNi/Ba0.6Sr0.4TiO3 Core-Shell Nanostructures

采用溶胶凝胶法制备了Ba0.6Sr0.4TiO3粉末,并采用球磨方法将Ba0.6Sr0.4TiO3与FeNi合金微粉进行包覆,成功制备了3种不同Ba0.6Sr0.4TiO3粉末添加量的FeNi/Ba0.6Sr0.4TiO3核壳结构粉体。采用SEM、XRD等技术分析了Ba0.6Sr0.4TiO3加入前后FeNi合金微粉的形态、组成,利用矢量网络分析仪测量了FeNi以及FeNi/Ba0.6Sr0.4TiO3复合材料的电磁参数。结果表明,成功制备了不规则颗粒状Ba0.6Sr0.4TiO3粉末,Ba0.6Sr0.4TiO3粉末大部分包覆于片状FeNi合金微粉表面,且随着Ba0.6Sr0.4TiO3粉末添加量的增加,包覆层厚度逐渐增大,FeNi合金片形态逐渐模糊。Ba0.6Sr0.4TiO3粉末包覆层有效降低了FeNi合金微粉的介电常数虚部,提高了其低频波段的阻抗匹配性能,实现铁电和铁磁双性材料的复合吸波效果,改善了低频吸波性能。利用1/4波长干涉相消理论对反射损耗峰频率与电磁参数关系进行了分析,并结合界面反射模型及材料阻抗匹配对反射损耗峰强度变化进行了分析。

Ba0.6Sr0.4TiO3 powder was prepared by sol-gel method,and Ba0.6Sr0.4TiO3 was mixed with FeNi alloy powder by ball milling method.FeNi/Ba0.6Sr0.4TiO3 composite with three different Ba0.6Sr0.4TiO3 powders was successfully prepared.The morphology and composition of FeNi alloy micropowder before and after the addition of Ba0.6Sr0.4TiO3 were analyzed by scanning electron microscopy and X-ray diffractometry.The electromagnetic parameters of FeNi and FeNi/Ba0.6Sr0.4TiO3 composites were measured by vector network analyzer..The results show that the irregular granular Ba0.6Sr0.4TiO3 powder can be successfully prepared.The Ba0.6Sr0.4TiO3 powder is mostly coated on the surface of the flake FeNi alloy powder,and with more Ba0.6Sr0.4TiO3 powder addition,the thickness of the coating gradually increases,and the shape of the FeNi alloy is gradually blurred.The Ba0.6Sr0.4TiO3 powder coating layer effectively reduces the dielectric loss of the FeNi alloy micropowder,improves the impedance matching performance in the low frequency band,and improves the low frequency absorbing performance.The relationship between the peak frequency of reflection loss and electromagnetic parameters was analyzed by 1/4 wavelength interference cancellation theory.The reflection intensity peak intensity was analyzed by interface reflection model and material impedance matching.