钛酸钡/钡铁氧体核/壳粒子的电磁性能

Electromagnetic Properties of BaTiO_3/BaFe_(12)O_(19) Core/Shell Particles

在以尿素为沉淀剂制备钛酸钡（BaTiO3）/钡铁氧体（BaFe12O19）核/壳粒子的基础上, 采用透射电子显微镜（TEM）、X射线衍射分析仪（XRD）、傅里叶变换红外光谱仪（FT-IR）对BaTiO3/BaFe12O19核/壳粒子前驱物及BaTiO3/BaFe12O19核/壳粒子的形貌、结构和成份进行了表征, 采用网络矢量分析仪对BaTiO3/BaFe12O19核/壳粒子的电磁特性进行了研究. 结果表明, 均匀共沉淀制得的BaTiO3/BaFe12O19粒子呈现核/壳结构, BaFe12O19壳层对BaTiO3的包覆均匀、完整、光滑; 在2－7GHz, BaTiO3/BaFe12O19核/壳粒子的ε′和ε″分别为10.7－17.0和0.3－0.6, 均高于BaTiO3. ε′和ε″的增大是核/壳结构所引起的界面极化加强的结果; BaTiO3/BaFe12O19核/壳粒子出现了BaTiO3所没有的磁性能, 其μ′和μ″在2~7GHz远远高于BaTiO3, 表现出了较为明显的磁损耗, 这与磁性BaFe12O19壳层的包覆有关.

Based on the homogeneous coprecipitation synthesis of BaTiO3/BaFe12O19 core/shell particles by using urea as precipitator,transmission electron microscope（TEM）,X-ray diffraction（XRD） and Fourier transform infrared（FT-IR） were used to characterize the morphology,structure and composition of BaTiO3/BaFe12O19 core/shell particles precursor and BaTiO3/BaFe12O19 core/shell particles,respectively.Network vector analyzer was used to study the electromagnetic properties of the BaTiO3/BaFe12O19 core/shell particles in 2 7GHz.The results indicate that,BaTiO3/ BaFe12O19 particles exhibited core/shell structure.The BaFe12O19 shell coated on the surface of BaTiO3 is uniform,integrate and smooth.In 2 7 GHz,the real part（ε′） and the imaginary part（ε″） of permittivity of BaTiO3/BaFe12O19 core/shell particles are in the range of 10.7 17.0 and 0.3 0.6,which are larger than that of BaTiO3.The increase of permittivity is a result of enhanced interfacial polarization caused by core/shell structure.BaTiO3/BaFe12O19 core/shell particles exhibited magnetic properties which are not existent in BaTiO3.BaTiO3/BaFe12O19 core/shell particles possess much larger real part（μ′） and imaginary part（μ″） of permeability than that of BaTiO3 and shown obvious magnetic loss in 2 7 GHz,which is owed to the coating of magnetic BaFe12O19 shell.