Effect Of Low-temperature Preparation On Megnetic Properties Of NiCuZn Ferrites

In order to get the NiCuZn ferrite materials with a excellent performance at a low temperature,we dop V2O5、Bi2O3、WO3 and Bi2O3-V2O5、Bi2O3-WO3 with a clear fomula. By adjusting an appropriate doping,we use the oxide way and get the NiCuZn ferrite materials with better property and low temperatures at 13.56 MHz. Meanwhile,we compare and analyze the influence with different flux to the microstructure and electromagnetic properties of the NiCuZn ferrite materials.On the basis of the theory, this paper expound the crystal structure 、 ion distribution、the way of super exchange and the other basic theory of the NiCuZn ferrite materials. Then,this paper describe the permeability、the cutoff frequency and other important parameters. At last,we analyse and explain the sintered properties of the NiCuZn ferrite materials and the significance of low-temperature sintering characteristics.Before the second milling,we add V2O5 and Bi2O3,and achieve a low-temperature sintering under 950℃ with a good performance. Adding different amounts of V2O5 and Bi2O3, at first, the permeability increased and then decreased, it suggest that the liquid mechanism can help to reduce the sintering temperature, but with flux levels continue to rise, it will produce grain growth abnormally and increase bubbles, resulting in performance degradation. Adding Bi2O3 can get high conductivity and low loss ferrite material with a low-temperature sintering, adding V2O5 with low-temperature sintering will get high conductivity and high loss ferrite material. Follow by a WO3 doping,it can not lower the sintering temperature, for a certain grain growth inhibition, permeability will be decreased, but the quality factor Q has significantly improved.According to the performance of the single doping, we dop Bi2O3-V2O5 and Bi2O3-WO3. The results shows that basis of the same content of doped Bi2O3, dopping V2O5 will cause the permeability elevated,and adding WO3 will improve the quality factor Q, however,it will significantly lower permeability.To further improve the performance, we analyze the influence of the milling time、the calcined temperature and the sinted temperature to the properties of the NiCuZn ferrite materials. With the increasing of the milling time、Calcining temperature and sintering temperature, all the permeability presented first and then decreased. With the increasing of the milling time, the crystal grains crush, the sintering activity be stronger,but then it will cause the introduction of impurities which cannot help to improve performance. Calcining temperature rises, the crystal grains grow and it will reduce the sintering activity. With the sintering temperature increases too high, it will cause uneven growth, abnormal grain and the bubble,which is not conducive to improve the magnetic properties.