Egg White Way To Preparation Of Ni-cu Ferrite Powders And Ceramic Materials

Ni-Cu ferrite is a kind of low temperature sintered ferrite material with extensive use. It is widely used in multiple accesses, switching powder supplies, various recording heads of audio and video, information storage systems, medical diagnosis, and so on. In recent years, as the rapid development of radios, mobile phones and television, especially the wider use of ferrite on chip inductors, EMI and RFI, the requirements on the Ni-Cu ferrite materials are higher and higher. The method using fresh egg white as composite complexing agent to prepare ferrite is a new method, which is a more simple process than co-deposition method and unnecessary to control the PH value of the mixture.This paper study on the preparition of Ni-Cu ferrite fine particle and ceramics, then research the technological conditions of preparation, phase and their property of magnetic performance etal. The main works are as following:Ni0.6Cu0.4Fe2O4fine particles were synthesized with Ni(NO3)3·6H2O, Cu(NO3)2·3H2O, Fe(NO3)3·9H2O, Zn(NO3)2·6H2O and egg white. The better technological conditions of preparation were gained. Ni(1-x)CuxFe2O4(x=0,0.2,0.4,0.6,0.8) and Ni0.25Cu0.25Zn0.5Fe2O4fine particles were synthesized at this technological conditions. By the determination of XRD, particle size and hysteresis loop, the better technological conditions with egg white as composite complexing agent is:240℃/1h-440℃/2h-520℃/6h. Ni0.6Cu0.4Fe2O4powder samples have smaller particle size, relatively uniform particle size distribution, and relatively good magnetic properties.With Ni(NO3)3·6H2O, Cu(NO3)2·3H2O, Fe(NO3)3·9H2O, Zn(NO3)2·6H2O as raw material and egg white as composite complexing agent, Ni1-xCuxFe2O4(x=0.0,0.2,0.4,0.6,0.8) and Nio.25Cuo.25Zno.5Fe2O4ceramics were sintered by solid-state reaction. This paper lays emphasis on the research of the sintering temperature and copper content to impact Ni-Cu ferrite microstructure and properties.The investigation of ceramic samples of microscopic structure and content of ceramic samples used XRD analysis and metallographic analysis and magnetic conductivity μ,dielectric parameters sr and resistivity p had been tested and analyzed, so as to gradually improve ferrite ceramic materials preparation techniques. The results of the study show that:Using fine powder maked for the formation of the major phase of ferrite, but it was easy growing up CuO impurity pharse and emerging abnormal grain growth when the sintering temperature rising; through magnetic conductivity, electrical resistivity and dielectric constant of the sample spectrum analyzed showing that, the magnetic conductivity and electrical resistivity of the content x=0.4of Ni1-xCuxFe2O4(x=0.0,0.2,0.4,0.6,0.8) ferrite ceramic materials is largest in frequency106～108Hz at room temperature; The magnetism performance of Ni0.25Cu0.25Zn0.5Fe2O4ceramic samples is better than Ni1-xCuxFe2O4.