Hydrothermal Synthesis Of Nickel Zinc Ferrite And Characterization

The characteristics, applications and technological research of soft magnetic ferrite material are summarized in this paper. The development tends of ceramic and problems to be solved are described briefly. Magnetic materials are the hot research nowadays in the field of magnetic materials. Ni-Zn ferrite as an important soft magnetic material and absorbing material will have a bright prospect.Ni-Zn ferrite powders were prepared by hydrothermal method through adding additives. The technical condition of preparation and the influence of template (triethylamin and polyethylene glycol) and La³⁺ and Ti⁴⁺ on Ni-Zn ferrite powders' morphology, particle size and structure were studied. The effects of different template and doping content of La³⁺ and Ti⁴⁺ on Ni-Zn ferrite performance were emphasized.The results showed: temperature(T), time(t) and addictive were the key factors influenced hydrothermal preparation. The products were characterized by XRD, SEM techniques and so on. When the temperature was less than 180℃, hydrothermal crystallization process was very slow and products were amorphous power which were agglomerate. It is favorable for enhancing hydrothermal crystallization process to increase temperature and time. When adding some addictives, small parts of impurity phase was eliminated and single crystal Ni-Zn ferrite was obtained. They are completely crystallized. Their size distribution is narrow and particle size is 20～30nm.According to the principle of zeolite, the micropore Ni-Zn ferrites were prepared when adding template. The products were spinel type. Porous structures were formed and the average of aperture is about 14nm. The density debased. The results of SEM showed that particles of products were small, particle-size distribution was uniform and dispersibility was good. The template was good for absorbing wave of Ni-Zn ferrite.La³⁺ iron had an effect on the growth of Ni-Zn ferrite powder. La iron(8%) can change the growth direction of Ni-Zn ferrite powder. cubic crystallites became anomalous circular. Ti⁴⁺ iron had no evident effect on the size and structure of crystal grain.鈽匱he results of magnetic performance and absorbing wave performance showed: La³⁺ and Ti⁴⁺ which have not magnetism debased saturation magnetization intensity of material. La³⁺ iron had a great effect on density and enhanced the absorbing wave performance of Ni-Zn ferrite. The highest absorption amount reach-30dB. When the doping content added, the absorption peaks moved to the low frequnency. The highest absorption amount when adding Ti⁴⁺ reach-35dB. So doping La³⁺ and Ti⁴⁺ properly will help to improve the absorbing wave performance of Ni-Zn ferrite.