镍锌钴铁氧体的水热低温合成与高频电磁性能研究

采用表面活性剂辅助水热法于160℃低温制备了NixZn1-xFe204(x=0.0、0.4、0.5、0.6)和Ni0.5Zn0.5FezCo0.01O4纳米粉体.XRD衍射和能谱分析表明,制备的铁氧体粉末具有单相尖晶石结构,由Scherrer公式计算出其平均粒径为10～30nm.随着Ni2+和Co2+的掺杂,样品的晶粒尺寸增加.红外光谱显示,在580cm-1附近出现铁氧体的特征吸收峰,随着Ni2+掺杂量的增加,特征吸收峰F3-O键向高频方向移动.软磁NiZnCo铁氧体的饱和磁化强度(Ms)为73.9emu/g,复介电常数的实部ε'和虚部ε"分别为11和1.3,复磁导率的实部μ'值在0.3GHz达到5,在1GHz下降到3,在0.5～3.0GHz的宽频范围内复磁导率的虚部μ"值大于1.铁氧体材料的低介电常数行为可应用于调控复合材料的介电常数以达到对高频电磁能的最大吸收,其特性可应用于微波吸收材料领域或在吉赫兹频率范围压抑电磁干扰.

Study on Low-temperature Hydrothermal Synthesis and High-frequency Electromagnetic Properties of NiZnCo-ferrite

Nano-powder Ni_xZn_(1-x)Fe_2O_4(x=0. 0,0. 4,0. 5,0. 6) and Ni_(0.5)Zn_(0.5)Fe_2Co_(0.01)O_4 are prepared by hydrothermal method with surfactant at 160℃.XRD analysis shows that the ferrite powder prepared have a single-phase spinel structure, and the average crystallite size is between 10~30nm by the Scherrer formula The grain size of sample increases by dopping Ni~(2+) and Co~(2+). Infrared spectra showes that the ferrite characteristic absorption peak presents at about 580cm~(-1). As the amount of Ni~(2+) increasing, the characteristic absorption of Fe-O bond moves to the high frequency. The saturation magnetization(M_s) of ferrite is 73. 9emu/g, the dielectric constant of NiZnCo-ferrite is about 11, the imaginary part of complex permittivity is 1. 3, the real part μ' of complex permeability for NiZnCo-fer-rite reaches 5 at 0. 3GHz and drops to 3 at lGHz,the imaginary part μ' of NiZnCo-ferrite is higher than 1 at 0. 5～3. 0 GHz. These ferrite materials with low dielectric constant behavior can be used for the filler of composite materials to obtain maximum absorption of electromagnetic energy in the GHz frequency range. These properties can be applied in the microwave absorbing materials field or suppressing electromagnetic interference in the GHz frequency range.