Preparation Of Mnzn Soft Ferrite Materials

High permeability materials can meet the requirements of miniaturization and lightweight of devices and systems because based on them less coils can get higher inductance due to their high permeability and smaller core. At the same time, the ferrite cores with high permeability can effectively absorb the electromagnetic interference signals, which can achieve the goal of anti-electromagnetic interference. With the electron products generally applied to the daily life, the problems of electromagnetic interference are becoming more and more serious, so investigation of high permeability materials is one of the good means to resolve this problem. Due to the development of information technology and electron product, the requirement of the high permeability materials increased sharply and their output reached 30 percent of the overall yield of ferrite. Thus study on the high permeability materials is the focus of the research in the world because of its high technical skills and addedvalue.In this paper, the conventional ceramic process of the R12K MnZn ferrite were studied. In the experiment, the effect of Fe2O3 and ZnO on the magnetic properties of ferrites, such as initial permeability (μi), saturation magnetic induction (Bs) was considered and the best formula of R12K MnZn ferrite was confirmed. Based on this formula, the influence of calcining temperature and rate of ball milling on initial permeability (μi), saturation magnetic induction (Bs), residual magnetic induction (Br) and coercive force (Hc) was discussed in detail. Furthermore, We analyzed the associated influence of dopants (CaCO3 ,V2O5 ,Bi2O3 and MoO3) on the magnetic properties of ferrites by adopting orthogonal design scheme. The main results were shown as follows:1,With the Fe2O3 content of the prescription increasing,μi showed the changing tendency of increasing at first and then decreasing, but Bs was always decreased and Hc was always increased.2,With the ZnO content of the prescription increasing,μi and Br were both increased at first and then decreased, but Bs and Hc were both decreased.3,The optimal mol ratio of Fe2O3, ZnO and MnO was 52 : 22 : 26.4,The rotational speed of a ball mill being too fast or too slow both lead to difficult grinding and mixing of powder particles, which could influence the magnetic properties of MnZn ferrite. The experiment results showed that the suitable secondary rotational speed was 210 r/min.5,Appropriate additive amount of V2O5 (0.06 wt%) can improve the comprehensive performance of materials. By the orthogonal design scheme, the optimal proportions of CaCO3 : Bi2O3 : MoO3 : V2O5 (wt%) is 0.02 : 0.05 : 0.06 : 0.02.6,The increasing of calcining temperature had an important effect onμi and Bs. Calcined under 840℃,μi and Bs of materials were both high.