Structural and Magnetic Properties of Zn and Co Substituted Nickel Ferrites Prepared by the Citrate Sol–Gel Method
Structural and Magnetic Properties of Zn and Co Substituted Nickel Ferrites Prepared by the Citrate Sol–Gel Method
复制标题
柠檬酸盐溶胶-凝胶法制备锌钴取代镍铁氧体的结构和磁性能
DOI：
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发表时间：
2013
影响因子：
1.8
通讯作者：
D. Yoon
中科院分区：
文献类型：
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作者：
K. Raju;D. Yoon
采用湿化学柠檬酸盐溶胶-凝胶法合成了NiFe2O4、Ni0.50Zn0.50Fe2O4和Ni0.50Zn0.25Co0.25Fe2O4三种铁氧体，主要研究了不同阳离子掺杂对铁氧体磁性能的影响。X-射线衍射仪(X射线衍射仪)证实了单相的存在，没有检测到杂质。采用Rietveld精细化技术对样品进行了X射线衍射分析，结果表明样品为立方尖晶石结构，空间群为FD-3m，并计算了其晶格常数。对焙烧样品的扫描电子显微镜显示，颗粒尺寸约为100 nm。能谱元素分析表明，所有样品的元素浓度均为化学计量比。用振动样品磁强计在室温下测量了镍铁氧体的磁性能，发现锌和钴的掺杂使镍铁氧体的磁性能得到了提高。用接近饱和定律模拟了磁滞回线的高场区域，以确定立方各向异性系数(K)。各向异性系数随掺入的锌、钴的增加而增大，这可以用掺杂在立方尖晶石晶格中的位置来解释。
Three different ferrites with nominal compositions, NiFe2O4, Ni0.50Zn0.50Fe2O4, and Ni0.50Zn0.25Co0.25 Fe2O4, were synthesized by wet chemical citrate sol–gel process, mainly to understand how doping with different cations affects the magnetic properties. X-ray diffraction (XRD) confirmed the existence of a single phase without detectable impurities. XRD analysis using the Rietveld refinement technique showed that the samples crystallize in a cubic spinel structure with the Fd-3m space group and the lattice constants were evaluated. Scanning electron microscopy of the calcined samples revealed particles that were approximately 100 nm size. The elemental analysis by energy dispersive spectroscopy showed that the element concentrations were at the stoichiometric ratio in all samples. The magnetic properties measured at room temperature using a vibrating sample magnetometer revealed enhancement in the magnetic properties of nickel ferrite when doped with zinc and cobalt. The high field regimes of the hysteresis loops were modeled using the Law of Approach to Saturation to determine the cubic anisotropy coefficient (K). The anisotropy coefficient increased with doping Zn and Co, which could be explained in terms of the site occupancy of the dopants in the cubic spinel lattice.