Hydrothermal Synthesis And Properties Of Rare Earth Elements Doped NiRE_xFe_2-xO₄(RE=Yb³⁺、La³⁺、Eu³⁺) Ferrite

The spinel ferrite is widely used in our daily life as a magnetic material, especially in communications equipments and magnetic devices. The development of spinel materials can improve the sophisticated technique, the speed of economic growth and the quality of life, so the research on the spinel ferrite has drawn a lot of attention. Ferrite materials have unique physical properties, chemical properties and magnetic properties.The properties of ferrite materials are closely related with the microstructure and the stoichiometry. The size, morphology and crystallinity of ferrite materials are closely related to the preparation methods of spinel ferrite.We introduced the features and classification of the ferrite magnetic materials in the first chapter of this paper, and the application, several kinds of preparation methods of ferrite magnetic materials were illustrated in the second chapter of this paper.In the experimental section, hydrothermal method were used to prepare nickel ferrite doped with rare-earth element ytterbium, lanthanum, europium ion. And we do the research about nickel ferrite containing rare earth elements(NiRExFe2-xO4, RE=Yb3+、La3+、Eu3+) in this study. The phase of as prepared sample suited by X-ray diffraction(XRD), magnetic properties test by vibrating sample magnetometer(VSM), morphology absorbed by transmission electron microscopy(TEM). From experimental results of the rare earth Yb3+,La3+ and Eu3+ ions doped sample, it is confirmed that rare element doping has not any effect on its’ shape, but particle size and saturation magnetization were decreased. NiYbx Fe2-xO4 ferrites ware obtained when doped with rare earth Yb3+ ions.With the increase of doping amount, samples’ size reduced from 47 nm to 18 nm,saturation magnetization reduced from 55.6 emu/g to 38.24 emu/g. NiLaxFe2-x O4 ferrites ware obtained When doped with rare earth La3+. After doping samples’ size reduced from47 nm to 22 nm, Saturation magnetization reduced from 55.6 emu/g to 39.21emu/g.When doped with rare earth Eu3+ get NiEuxFe2-xO4 ferrite,the same sample size from 47 nm reduced to 20 nm,saturation magnetization from 55.6emu/g ireduced to 36.56emu/g.Because of rare earth ions to controlled grain growth, so as the grain size will decrease with increasing amount of dopant, the product was manufactured grain refinement, with increasing amounts of doped rare earth element saturation magnetization and coercivity shown a downward trend. The Eu ion doping leaded the most obvious change on the magnetic properties of the sample. This series of experimental studies has very important theoretical and application value on improving magnetic properties of nickel ferrite.