Study On Doping Properties Of NiCuZn Ferrite And Sintering Properties Of ZnCo Ferrite

Since the beginning of the 21st century,electronic technology has developed rapidly,and electronic components have developed into multiple functions,miniaturization,high efficiency and multi-field.As a soft magnetic material,Ni-Cu-Zn ferrite and Zn-Co ferrite are widely used in the manufacture of related electronic devices in the fields of communication,measurement,military confrontation,due to their unique electromagnetic properties.Ni-Cu-Zn ferrite nanoparticles and Zn-Co ferrite nanoparticles were synthesized by sol-gel method.The effects of different doping amounts and doping elements on the structure and magnetic properties of Ni-Cu-Zn ferrite and the effects of different sintering temperatures on the structure and magnetic properties of Zn-Co ferrite were investigated.Studies have shown that the synthesized ferrite is a nano-scale cubic spinel structure,and both have excellent magnetic properties.The specific research contents are as follows:?1?The Ni_0.3Cu_0.2Zn_0.5Y_xFe_2-xO₄?where x=0,0.025,0.05,0.075,0.1?ferrite with Y³⁺substituted partial iron was synthesized by sol-gel method at 950?.The structure and magnetic properties of the sample were studied.It was found that a small amount of Y³⁺doping does not destroy the crystal structure of Ni-Cu-Zn ferrite,but when the doping amount is more than 0.025,a small amount of YFeO₃ foreign phase is formed.As the doping amount increases,the lattice constant first decreases and then increases,and the grain size and saturation magnetization increase first and then decrease.Compared with pure Ni_0.3Cu_0.2Zn_0.5Fe₂O₄ ferrite,the coercivity,remanence,squareness and Curie temperature of the doped samples increased,but all samples showed a paramagnetism.When the doping amount is 0.025,the saturation magnetization reaches 68.98 emu/g,and the Curie temperature increased to 215?.?2?Different ratios of La³⁺and Y³⁺doped Ni-Cu-Zn ferrite were prepared by sol-gel method at 950?.X-ray diffraction spectroscopy and Fourier transform infrared spectroscopy confirmed that the composites all had a spinel cubic structure,and it was found that doping a certain proportion of La³⁺and Y³⁺effectively suppressed the formation of impurity phases,However,when the amount of doping is large,a Fe₂O₃ foreign phase is formed.The sample after co-doping has a larger lattice constant,coercivity,and remanence compared to pure Ni-Cu-Zn ferrite.The saturation magnetization has a certain relationship with the doping ratio of Y³⁺and La³⁺.When the doping amounts of Y³⁺and La³⁺are the same,the synthesized ferrites have similar and small saturation magnetization,but when La³⁺is higher than Y³⁺by0.025,that have almost the same saturation magnetization.?3?The effects of sintering atmosphere and temperature on structural and magnetic properties of Zn_0.5Co_0.5Fe₂O₄ nanoparticles prepared by Sol-gel method have been studied.X-ray diffraction spectrum?XRD?,Fourier transform infrared spectroscopy?IR?and Vibrating Sample Magnetometer?VSM?were used to investigate the structures and magnetic properties of prepared samples,respectively.We tried to use theoretical knowledge to introduce the phenomena that appeared in the experiment.It has been found that the sintering temperature has a great influence on the structure and magnetic properties of Zn-Co ferrite.The crystallinity and grain size of the sample increase significantly with the sintering temperature increases from600? to 1000?.However,the coercivity,remanence and squareness of ferrite gradually decrease,the saturation magnetization increases firstly and then decreases.The saturation magnetization of the sample sintered at 900? is reached 68.17 emu/g.