Effect Of Doping On Properties Of High Permeability MnZn Ferrite

This paper discussed the basic process of the chemical coprecipitation preparation of Mn Zn ferrite, and Mn-Zn ferrites of high permeability were chemical doped, the doping elements was Ca, Bi and Ti.The effects on the properties of Mn-Zn ferrites with high permeability was analyzed.In order to improve the frequency characteristics of the ferrite material, Ca element was doped into Mn-Zn ferrite which molecular formula is MnxZn1-xFe2O4, and measured the curve of the initial permeability with frequency (i.e.μi-f curve) of the ring specimens. Study found that, with the increase of Ca content, the frequency characteristic is improved, in250Hz, the initial permeability can still be maintained at around10000. When the content of CaO was0.02mol, the materials had the best magnetic properties and microstructure. On the other hand, with the increase of CaO content, the speed of initial permeability decreases increased, which related to the doping location of Ca2+.This paper has also studied the effect of Mno.4Zn0.6F2O4on structure and magnetic ferrite material (including the magnetization, the initial permeability and the effect of grain size) by Bi2O3doping. The results showed that, when Bi2O3doping, the liquid phase sintering formed at700℃, the grain size of the materials significantly increased, and density increased. When the content was0.005mol, the initial permeability had an optimal value, the grain size increased significantly, and were more uniform. The magnetic properties of ferrite with Bi2O3doped was improved, as so as the microstructure was optimized. Experiments show that, with the increase of the Bi2O3content, the grain size of the material increased even appeared abnormal growth and inhomogeneity. This showed that, Bi2O3play the role of promoting grain growth.In addition, TiO2were doped, at the same time Bi2O3-CaO-TiO2were doped and studied.Through repeated tests, preliminary to determine the impact of doping of Mn-Zn ferrites with high permeability, by SEM, average particle size analyzing, initial permeability, XRD and XPS analyzing. XRD and XPS confirmed the structure of Mn-Zn ferrite, and determined the doping position, other tests proved that the effects of the doping on properties. Achieved good results, and provide a basis for the industrial application.