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.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | Cushing B L, Kolesnichenko V L, O'Connor C J. Recent advances in the liquid-phase syntheses of inorganic nanoparticles. Chemical Reviews, 2004, 104(9): 3893-3946.[2] Yang Z Z, Niu Z W, Lu Y F, et al. Templated synthesis of inorganic hollow spheres with a tunable cavity size onto core-shell gel particles. Angewandte Chemie-International Edition, 2003, 42(17): 1943-1945.[3] Melo L G C, Menard D, Ciureanu P, et al. Coupled core-shell model of magnetoimpedance in wires. Journal of Applied Physics, 2004, 95(3): 1331-1335.[4] Zeng T F, Liu W. Phonon heat conduction in micro- and nano-core-shell structures with cylindrical and spherical geometries. Journal of Applied Physics, 2003, 93(7): 4163-4168.[5] Van de Coevering R, Alfers A P, Meeldijk J D, et al. Ionic core-shell dendrimers with an octacationic core as noncovalent supports for homogeneous catalysts. Journal of the American Chemical Society, 2006, 128(39): 12700-12713.[6] Ivanov S A, Piryatinski A, Nanda J, et al. Type-II core/shell CdS/ZnSe nanocrystals: synthesis, electronic structures, and spectroscopic properties. Journal of the American Chemical Society, 2007, 129(38): 11708-11719.[7] Ravel B, Carpenter E E, Harris V G. Oxidation of iron in iron/gold core/shell nanoparticles. Journal of Applied Physics, 2002, 91(10): 8195-8197.[8] Huo Q S, Liu J, Wang L Q, et al. A new class of silica cross-linked micellar core-shell nanoparticles. Journal of the American Chemical Society, 2006, 128(19): 6447-6453.[9] Xu P, Han X J, Wang C, et al. Synthesis of electromagnetic functionalized nickel/polypyrrole core/shell composites. Journal of Physical Chemistry B, 2008, 112(34): 10443-10448.[10] Xu X B, Ge M Y, Wang C, et al. High temperature stable monodisperse superparamagnetic core-shell iron-oxide/SnO2 nanoparticles. Appl. Phys. Lett., 2009, 95(18): 183112-1-3.[11] Sacanna S, Philipse A P. A generic single-step synthesis of monodisperse core/shell colloids based on spontaneous pickering emulsification. Advanced Materials, 2007, 19(22): 3824-3826.[12] Cho S J, Kauzlarich S M, Olamit J, et al. Characterization and magnetic properties of core/shell structured Fe/Au nanoparticles. Journal of Applied Physics, 2004, 95(11): 6804-6806.[13] Lee S W, Drwiega J, Mazyck D, et al. Synthesis and characterization of hard magnetic composite photocatalyst - barium ferrite/ |
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