Study On The Preparation And Magnetic Properties Of Spinel Ferrite Nanocrystallites

Being a kind of magnetic materials possessing many characters, ferrite has been applied in magnetic recorders, magnet, magnetic liquid, and microwave materials and so on. At the same time, as a sort of composite oxide, ferrite has many applications, such as catalysis and environmental protection.In this work, several spinel ferrite nanocrystallites, including Ni-ferrite,Ni-Co ferrite and Ni-Mg compound ferrite, were prepared. The microstructures and characteristics of the products were studied by the helps of thermogravimetric and differential thermal analyses (TG-DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), etc.In this work, Ni-ferrite was prepared via sol-gel and coprecipitation method respectively. The analyzed result showed the grain of samples synthesized via sol-gel method were uniformity, and easily crystal. The influence of different preparative conditions, including molar rations of chelating agent to total metal ions, values of pH and calcined temperature, on the microstructures and characteristics and of the products were studied and discussed.The magnetic properties at room temperature of NiFe2O4,Ni0.5Co0.5Fe2O4,Ni0.5Mg0.5Fe2O4 nanocrystallites were analyzed by a vibrating sample magnetometer (VSM) respectively, and they showed different properties comparing with the bulk materials. The influences of preparative conditions on the magnetic properties of products were also discussed in this work.