共沉淀过程中镍锌添加比例对两步法制备的Ni_(0.5)Zn_(0.5)Fe_2O_4吸波性能的影响

Effect of proportion of nickel and zinc in coprecipitation method on absorption property of Ni_(0.5)Zn_(0.5)Fe_2O_4 prepared by two steps

采用共沉淀法和溶胶-凝胶法制备了纳米Ni_(0.5)Zn_(0.5)Fe_2O_4粉体。通过X射线衍射(XRD)、原子力显微镜(AFM)、矢量网络分析(VNA)等方法对4种不同添加比例的样品进行微观结构和电磁性能表征。结果表明:通过650℃煅烧,在4种添加比例下都得到了纯Ni_(0.5)Zn_(0.5)Fe_2O_4。制备的Ni_(0.5)Zn_(0.5)Fe_2O_4为球形,随着共沉淀过程中添加比例的增加,粒径先减小后增大,添加比例为60%时粒径最小,平均粒径约为44nm。在2～12.4GHz时,材料厚度越大,Ni_(0.5)Zn_(0.5)Fe_2O_4有效吸波频带越接近低频波段,且最大吸波强度达到-24.94dB。当添加比例为60%时,Ni_(0.5)Zn_(0.5)Fe_2O_4有效吸波频段为5.0～9.9GHz,有效吸波频带最宽,微波吸收性能最佳。

Nano Ni0.5Zn0.5Fe2O4 powders were prepared by the coprecipitation method combined with sol-gel method.The microstructure and electromagnetic performance of the as-prepared four kinds of Ni0.5Zn0.5Fe2O4 samples with different addition proportion were characterized by X-ray diffraction,atomic force microscope(AFM),vector network analysis(VNA).The results show that the pure Ni0.5Zn0.5Fe2O4 is gained in each proportion under 650℃calcination.The Ni0.5Zn0.5Fe2O4 particles are spherical,with the increase of adding proportion in coprecipitation process,particle size decreases first and then increases,the particles have the minimum size while the proportion is 60%,the average size is around 44nm.In the range of 2-12.4GHz,the greater the thickness of the material,the closer the effective absorption band of Ni0.5Zn0.5Fe2O4 is to the low frequency band,the maximum absorbing intensity of Ni0.5Zn0.5Fe2O4 can reach-24.94dB.While the proportion is 60%,the effective absorption band of Ni0.5Zn0.5Fe2O4 is 5.0-9.9GHz,the bandwith reaches maximum,and microwave absorption property is the best.