The Zn0.5CuxMg0.5-xFe2O4 (where x = 0.0, 0.1, 0.2, 0.3 and 0.4) was prepared by sol-gel route and characterized in detail in terms of their structural, morphological, elemental and optical properties as a function of ...The Zn0.5CuxMg0.5-xFe2O4 (where x = 0.0, 0.1, 0.2, 0.3 and 0.4) was prepared by sol-gel route and characterized in detail in terms of their structural, morphological, elemental and optical properties as a function of Cu concentration. X-ray diffractometer (XRD) results confirmed the formation of cubic spinel-type structure with average crystallized size in the range of 30.56 to 40.58 nm. Lattice parameter was found to decrease with Cu concentration due to the smaller ionic radius of Cu2+ ion. The HR-SEM images show morphology of the samples as prismatic shaped particles in agglomeration. The elemental dispersive X-ray Spectroscopy (EDX) confirmed the elemental composition of the as-prepared spinel ferrite material with respect to the initial concentration of the synthetic composition used for the material. The Fourier transform infrared (FTIR) spectroscopy confirmed the formation of spinel ferrite and showed the characteristics absorption bands around 463, 618, 876, 1116, 1442, 1622 and 2911 cm-1. The energy band gap was calculated for the samples were found to be in the range of 4.87 to 5.30 eV.展开更多
Ni(Co/Zn/Cu)Fe_2O_4/SiC@SiO_2, a microwave absorber, was prepared by the sol-gel method. The phase structure and the morphology of the microwave absorbers were characterized by X-Ray Diffraction(XRD) and scanning elec...Ni(Co/Zn/Cu)Fe_2O_4/SiC@SiO_2, a microwave absorber, was prepared by the sol-gel method. The phase structure and the morphology of the microwave absorbers were characterized by X-Ray Diffraction(XRD) and scanning electron microscopy(SEM), respectively. Laser sizer(LS) and X-ray photoelectron spectroscopy(XPS) analysis show the core-shell structure of SiC@SiO_2. Coaxial method was used to measure the microwave absorption properties of the prepared composites in the frequency range of 2-18 GHz. When 70 wt% SiC is wrapped by 30 wt% SiO_2,and 50 wt% NiFe_2O_4 is added into 50 wt% SiC@SiO_2, the as-prepared powders are found to have advanced microwave absorption properties with a minimum reflection loss(RL) of -32.26 dB at about 6.08 GHz, and the available bandwidth is approximately 2.1 GHz when the RL is below -10 dB.展开更多
文摘The Zn0.5CuxMg0.5-xFe2O4 (where x = 0.0, 0.1, 0.2, 0.3 and 0.4) was prepared by sol-gel route and characterized in detail in terms of their structural, morphological, elemental and optical properties as a function of Cu concentration. X-ray diffractometer (XRD) results confirmed the formation of cubic spinel-type structure with average crystallized size in the range of 30.56 to 40.58 nm. Lattice parameter was found to decrease with Cu concentration due to the smaller ionic radius of Cu2+ ion. The HR-SEM images show morphology of the samples as prismatic shaped particles in agglomeration. The elemental dispersive X-ray Spectroscopy (EDX) confirmed the elemental composition of the as-prepared spinel ferrite material with respect to the initial concentration of the synthetic composition used for the material. The Fourier transform infrared (FTIR) spectroscopy confirmed the formation of spinel ferrite and showed the characteristics absorption bands around 463, 618, 876, 1116, 1442, 1622 and 2911 cm-1. The energy band gap was calculated for the samples were found to be in the range of 4.87 to 5.30 eV.
基金financially supported by the Military Project of the Ministry of National Defense of China (No. JPPT-125-2-168)
文摘Ni(Co/Zn/Cu)Fe_2O_4/SiC@SiO_2, a microwave absorber, was prepared by the sol-gel method. The phase structure and the morphology of the microwave absorbers were characterized by X-Ray Diffraction(XRD) and scanning electron microscopy(SEM), respectively. Laser sizer(LS) and X-ray photoelectron spectroscopy(XPS) analysis show the core-shell structure of SiC@SiO_2. Coaxial method was used to measure the microwave absorption properties of the prepared composites in the frequency range of 2-18 GHz. When 70 wt% SiC is wrapped by 30 wt% SiO_2,and 50 wt% NiFe_2O_4 is added into 50 wt% SiC@SiO_2, the as-prepared powders are found to have advanced microwave absorption properties with a minimum reflection loss(RL) of -32.26 dB at about 6.08 GHz, and the available bandwidth is approximately 2.1 GHz when the RL is below -10 dB.
