Researching And Preparation Of High-performance Of M-type Ferrite

M-type strontium ferrite (SrM) as important permanent magnet materials, has a wide range of applications in magnetic devices, permanent magnet motor and a variety of filtering devices. The most productions of the strontium ferrite is produced by china in the world. There are many ways of preparing ferrite, solid phase reaction production process is simple and easy to control, more suitable for mass production.In this paper, studying solid state reaction (ceramic method) for preparation of M-type strontium ferrite, the proper ratio of raw materials and nano-additives on the strontium ferrite phase, morphology and magnetic properties. Using SrCO3(99%) and Fe2O3(99%) as raw materials.Through milling, drying, magnetic forming, sintering and other processes in order to get M-type strontium ferrite final sample. Using X-ray diffraction, SEM, Measuring device to analysis phase,size and shape of particles, magnetic remanence and intrinsic coercivity of the ferrite.The results show that:(1) rare earth La, Co ions can be replaced in the strontium ferrite Sr, Fe ion, added to enhance the strontium ferrite single remanence. (2) common additives Al2O3, SiO2, CaCO3 can greatly improve the strontium ferrite coercivity and remanence. Magnetic properties can achieve higher standards (3) the experimental formula 6 prepared in the magnetic properties is the ideal one. When sintering temperature is 1200℃, the magnetic properties of the sample can reach FB5B comprehensive standard. (4) using nanometer-scale materials (strontium carbonate and iron oxide) is required for lower calcining temperature,which is lower than the temperature of appearing of M phase of non-nano materials about 150℃. (5) for the same calcining temperature, nano-particle has well growth and is smaller than the size of micron samples.(6) When the sintering temperature is 1150℃, the nano-magnetic materials samples gets the best(Br=372mT, Hcj=375KA/m), the temperature of the sample is lower than micron sample temperature about 100℃.And in the magnetic properties the nano-sample is better than the sample which is not used the raw nano-materials.