Abstract This paper addresses the manipulation of structural, morphology, optical and magnetic properties of LiCo0.25Zn0.25Fe2O4 ferrite via incorporation of different proportions of La3+ at the expense of iron ions using a sol-gel method. The samples were characterized using the X-ray diffraction technique (XRD), Fourier transform infrared (FT-IR) spectroscopy, the energy dispersive X-ray spectra (EDX), inductively coupled plasma optical emission spectroscopy (ICP-OES), high resolution scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, ultraviolet-diffuse reflectance spectroscopy (UV-DRS), and vibrating sample magnetometer (VSM) technique. The Rietveld refinements of the samples indicate that at higher concentrations of La3+, nanostructures with dual phase, i.e. cubic spinel and orthorhombic LaFeO3 perovskite with space group (Pbnm) appear. Optical studies show that the energy band gap (Eg) of the bare LiCo0.25Zn0.25Fe2O4 ferrite sample (2.18 eV) reaches up to 2.47 eV at x = 0.06 and above this concentration, it drops sharply to 2.00 eV. Although the saturation magnetization and the coercivity of LiCo0.25Zn0.25LaxFe2–xO4 are lower than that of LiCo0.25Zn0.25Fe2O4 NPs. Overall, the superparamagnetic nature and low values of saturation magnetization and coercivity of LiCo0.25Zn0.25LaxFe2-xO4 NPs are suitable to be applied in transformers core.

中文翻译：

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La3+ 掺杂的 LiCo0.25Zn0.25Fe2O4 尖晶石铁氧体纳米晶体：结构、光学和磁性能的见解

摘要 本文通过溶胶-凝胶法以铁离子为代价，通过掺入不同比例的 La3+ 来处理 LiCo0.25Zn0.25Fe2O4 铁氧体的结构、形态、光学和磁性能。使用 X 射线衍射技术 (XRD)、傅里叶变换红外 (FT-IR) 光谱、能量色散 X 射线光谱 (EDX)、电感耦合等离子体发射光谱 (ICP-OES)、高分辨率对样品进行表征扫描电子显微镜 (SEM)、Brunauer-Emmett-Teller (BET) 表面积分析、紫外漫反射光谱 (UV-DRS) 和振动样品磁强计 (VSM) 技术。样品的 Rietveld 改进表明，在较高浓度的 La3+ 下，具有双相的纳米结构，即 立方尖晶石和具有空间群 (Pbnm) 的正交 LaFeO3 钙钛矿出现。光学研究表明，裸 LiCo0.25Zn0.25Fe2O4 铁氧体样品 (2.18 eV) 的能带隙 (Eg) 在 x = 0.06 时达到 2.47 eV，并且在此浓度以上，它急剧下降至 2.00 eV。尽管 LiCo0.25Zn0.25LaxFe2–xO4 的饱和磁化强度和矫顽力低于 LiCo0.25Zn0.25Fe2O4 NPs。总的来说，LiCo0.25Zn0.25LaxFe2-xO4 NPs的超顺磁性和较低的饱和磁化强度和矫顽力适合应用于变压器铁芯。尽管 LiCo0.25Zn0.25LaxFe2–xO4 的饱和磁化强度和矫顽力低于 LiCo0.25Zn0.25Fe2O4 NPs。总的来说，LiCo0.25Zn0.25LaxFe2-xO4 NPs的超顺磁性和较低的饱和磁化强度和矫顽力适合应用于变压器铁芯。尽管 LiCo0.25Zn0.25LaxFe2–xO4 的饱和磁化强度和矫顽力低于 LiCo0.25Zn0.25Fe2O4 NPs。总的来说，LiCo0.25Zn0.25LaxFe2-xO4 NPs的超顺磁性和较低的饱和磁化强度和矫顽力适合应用于变压器铁芯。