Study On Structure, Magnetic Properties And Cation Distributions In Cu_1-xZn_xFe₂O₄å'ŒCu_0.5-xNi_0.5Zn_xFe₂O₄Materials

Ferrites are the transition metal oxides, which possess ferrimagnetism, with highresistivity，high Curie temperature，small magnetic coercivity，low eddy current，lowdielectric loss，high temperature resistance，corrosion resistance and excellent chemicalstability. Ferrites are widely applied in electrical devices, such as information storage andmicrowave devices,The spinel ferrite is repesented by the formula MFe₂O₄, in which oxygen ions arrangewith face certer cubic structure, and the metal ion at （A） and [B] site are surrounded by fourand six oxygen ions at equal distances, respectively. The methods of estimating cationdistribution of spinel ferrite include X-ray diffraction （XRD），Mossbauer spectroscopy andX-ray absorption fine structure （EXAFS） and so on.In the paper，Spinel ferrite samples with composition Cu_1-xZn_xFe₂O₄（0.0≤x≤1.0） andCu_0.5-xNi0.5Zn_xFe₂O₄（0.0≤x≤0.5） have been synthesized by chemical co-precipitation.Thecrystal structure of the samples was identified through X-ray diffraction （XRD） using anX’pert Pro diffractometer at room temperture. The magnetic properties of the samples weremeasured using a Physical Properties Measurement System （PPMS）. The cation distributionsin the samples were estimated using the quantum mechanical method proposed by our group.It is found that:（1） All the samples have a single phase cubic spinel structure，with space groupFd3m.The lattice constant of samples increased with increasing Zn content. The crystallitesize of all the samples without Zn are more smaller, and that of the samples doped Zn arelarge. However, there are no notable variation of dependence of the crystallite size on the Zndoped content.（2） The saturation magnetization of the samples with composition Cu_1-xZn_xFe₂O₄（0.0≤x≤1.0） increased with increasing Zn content，when x≤0.4; and then decreased withincreasing x. The saturation magnetization of the samples with compositionCu_0.5-xNi0.5Zn_xFe₂O₄（0.0≤x≤0.5） increased with increasing Zn content. Curie temperture of thetwo series samples decreased with increasing Zn content.（3） Using the measured magnetic moments，the cation distributions in （A） site and [B]site of the samples were estimated using a quantum mechanical method proposed by ourgroup. By adopting the estimated cation distributions，the X-ray diffraction pattern of the samples were fitted using the Full Prof-Suite software. The various error indicator parameterslay within acceptable ranges, indicating that our quantum mechanical method is effective forestimating the cation distributions in spinel ferrites.