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

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(e′) and the imaginary part(e″) 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.