| With the high speed development of Microelectronics Technology, Advanced Manufacturing Technology and the fourth generation information network communication technology, electronic equipment gradually tend to be small, lightweight, intelligence, functional integration, high density storage and super fast transmission, such as the portable mobile devices like mobile phones, ipad, notebook computers, digital cameras, digital video cameras, MP3, MP4and so on. In turn, new and higher requirements will be proposed for the Muitilayer Chip Inductor (MLCI) that with the chip structure as the main characteristics. NiCuZn spinel ferrite is one of the soft magnetic materials best suitable for application in MLCI because of its properties at high frequency, such as high chemical stability, initial permeability, electrical resistiviyty and lower magnetic loss. MLCI is an electronic devices with the structure of alone petrochemical, and it is constituted with laminated alternating multilayer printed by using ferrite slurry and Ag electrodes as raw materials, then sintered with low temperature co-fired technology (LTCF), due to the melting point of Ag is961℃, So it requires to develop high performance low temperature sintering NiCuZn soft magnetic materials with the development trend, and the precondition of acquiring high performance NiCuZn ferrite ceramics is achieving fine and uniform NiCuZn ferrite powder, and it is also the basis of getting good MLCI products.Egg white protein besides its high nutritional protein, but also has strong adsorption, foaming, gelling and emulsifying characteristics, it is an economical, simply, reaction conditions and environmentally friendly method for preparing ferrite powder by using egg white as composite complex. In this paper, the effect of Cu and Zn content on the properties of powder and ceramic of Ni1-xCuxFei.96O4and Ni1-xZnxFe1.96O4ferrite will be investigated, respectively. On this basic, the effect rule of composition and technology factors on the properties of NiCuZn ferrite powder and ceramic which prepared by using egg white will be studied, such as nitrate concentration, egg white concentration, sintering temperature, preburning or not, calcining temperature, calcining insulation time, heating rate and lacking of iron ratio, then getting the relatively good preparation conditions. To further improve the permeability and electromagnetic at high frequency of NiCuZn ferrite, using the filtered technology system, trying to prepare the NiCuZn ferrite that using as addition agent, and studying on the effect rule of the NiCuZn ferrite properties with different content of Nd2O3.XRD, grain size and hysteresis loop were carried out to investigate on Nii-xCuxFei.96O4(x=0.4,0.5,0.7) and Nii-xZnxFei.96O4(x=0.4,0.5,0.7,0.75) ferrite powder, that prepared under the conditions of using dilute egg white (Vcgg:Vdistilled=3:2) as composite complex, nitrate concentration was controlled on0.5mol/L and sintered at240℃-1h-440℃-2h-760℃-12h with the heating rate of100℃/h. The results revealed that it had better applicability by using egg white method to prepare the single phase of dualistic Ni1-xCuxFei.9604and Ni1-xZnxFe1.96O4fine ferrite powder, the ferrite powders with the proportion of Nio.6Cuo.4Fe1.96O4and Nio.5Zno.5Fe1.96O4were got the better comprehensive performance, the average particle size was59.45nm and49.95nm, respectively, and the saturation magnetization was29.63A·m2·kg-1and37.82A·m2·kg-1. On this basic, testing and analyzing on the properties of NiCuZn powder samples that prepared by using egg white method. The results revealed that egg white method also had better applicability to prepare the single phase of triaxial NiCuZn fine ferrite powder, the btter composition and process conditions were:using iron deficiency ration, nitrate concentration was controlled on0.5mol/L, dilute egg white used as composite complex, sintered at240℃-1h-440℃-2h-760℃-12h with the heating rate of100℃/h before700℃, then50℃/h.On those conditions, the average particle size of Nio.25Cuo.25Zno.5Fe1.96O4ferrite powder was48.34nm, the values of D50was0.14μm, and the saturation magnetization was161.95A m2·kg-1.Using the conventional calcining method, as to the Ni1-xCuxFe1.96O4,Ni1-xZnxFe1.96O4and NiCuZn ferrite ceramic samples that after calcination.XRD, electrical resistivity, SEM, permeability, dielectric constant, density and dielectric loss tangent were carried out to investigate the properties of them. The results revealed that the Cu and Zn content had a significant influence on the electrical and magnetic properties, it was agree with the results of powder, and the properties of NiZn ferrite was significant better than NiCu ferrite’s. The measurement results of NiCuZn ferrite revealed that, the better preparation conditions were using the powder that synthesized by using dilute egg white and sintering at760℃for12h, cancelling the preburning session, directly calcining at950℃for3h with the slowly heating rate. On this condition, the maximum values of permeability could be get to36.2.Testing and analysis on the performance of Ni0.25Cu0.25Zn0.5Fe1.96O4ferrite powder and ceramic samples that incorporation of xNd2O3(x=0,0.2%,0.4%,0.6%,0.8%) dopants. The results indicated that small amount of secondary phase of iron neodymium oxide existed in the ferrites doped with Nd2O3, and the relative intensity of the secondary phase peaks increases with increasing amount of Nd2O3; small amount of Nd2O3incorporated into NiCuZn ferrite can result in the increase of the saturation magnetization, the non-uniformity of particle size, and enlargement the porosity, benefit for improving electrical resistivity, reducing eddy current loss, however, it was worse for the permeability at high frequency, lower the cutoff frequency, this may be related to the second phase. |
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