Preparation And Study Of Magnetic Properties Of Rare Earth Doped NiFe₂O₄ Nanowires

In the paper,metal nitrates were used as raw materials,and anhydrous ethanol and distilled water were used as solvent and citric acid was used as the complexing agent of metal cation in solution while polyvinylpyrrolidone?PVP?was used as a viscous agent.The one-dimensional spinel structure of NiFe₂O₄ and NiFe_2-xRE_xO₄?RE=Pr,Nd,Sm;x=0?0.02?0.04?0.06?0.08?0.1?nanowires have been fabricated by using sol-gel method,electrospinning technique and heat treatment technology.The structure,morphology and magnetic properties of NiFe₂O₄ and NiFe_2-xRE_xO₄?RE=Pr,Nd,Sm;x=0⁰.1?nanowires are characterized by X ray diffraction?XRD?,Fourier transform infrared spectroscopy?FT-IR?,scanning electron microscopy?SEM?and vibrating sample magnetometer?VSM?.The results showed that:The continuous NiFe₂O₄ nanowires with smooth surface and uniform diameter and diameter sizes of 60 nm and a well-developed spinel structure were successfully obtained after calcining at 500?⁹00?.The NiFe₂O₄ nanowires had a good quality of soft magnetic properties and the saturation magnetization?Ms?and remanent magnetization?Mr?increased with the rise of calcination temperature.Ms and Mr reached the maximum value of 35.56 emu/g and 13.29 emu/g after calcining at 900?.Nanowires with Ms of 30.56 emu/g and coercivity?Hc?reached a maximum value of219.65 Oe at 600?.NiFe₂O₄ nanowires optimal calcination temperature is 800?.The Ni Fe_2-xRE_xO₄?RE=Pr,Nd,Sm;x=0⁰.1?nanowires surface is smooth and the diameter of the nanowires is about 60 nm which is continuous and symmetrical.Doping rare earth Pr³⁺,Nd³⁺and Sm³⁺does not change the spinel structure of NiFe₂O₄,which reduced the crystallinity and crystallite size of NiFe₂O₄.The NiFe_2-xRE_xO₄?RE=Pr,Nd,Sm;x=0⁰.1?nanowires exhibit soft ferrimagnetic behavior.Doping rare earth Pr³⁺,Nd³⁺and Sm³⁺respectively reduced Ms of NiFe₂O₄ nanowires,and with the increase of doping Pr³⁺and Sm³⁺,Ms of the nanowires to reduce the widespread law,and Ms regularity of doped rare earth Nd³⁺NiFe₂O₄ nanowires is not obvious.The Hc of NiFe₂O₄ nanowires is reduced after doping with rare earth Pr³⁺,Nd³⁺and Sm³⁺,respectively.With the increase of Pr³⁺,Nd³⁺and Sm³⁺doping,Hc gradually decrease,respectively.Magnetic distance and ion radius of rare earth element ion,and the crystallite size,magnetocrystalline anisotropy and Spin-Orbit Coupling of NiFe_2-xRE_xO₄?RE=Pr,Nd,Sm;x=0⁰.1?nanowires were observed in the magnetic properties variation of NiFe_2-xRE_x O₄?RE=Pr,Nd,Sm;x=0⁰.1?nanowires play a very important role.