Electromagnetic Properties of BaTiO3/BaFe12O19 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 (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.