Impact of rare-earth ions (Ce, La, Sm) doping on the lattice structure and magnetic characteristics of barium cobalt nano-ferrite

Abstract

In order to optimize the structure and magnetic properties of Ba-CO nano-ferrite, rare-earth ions-doped Ba_0.2Co_0.8Fe_2-xRE_xO₄ (RE = Sm, Ce, La and x = 0.02) nanopowder was prepared by sol–gel method at 950 °C. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used for the structural analysis. The presence of few additional phases (BaFe₂O₄) was found in the doped samples. After the RE ions doping, the lattice constant calculated from the XRD patterns increased to 8.3791 Å. The morphology of the material was studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). Energy-dispersive spectrometer analysis (EDS) confirmed that there are corresponding rare-earth elements, as well as Ba, Co, and O elements in the sample. The binding energy of La-doped barium cobalt nano-ferrite was studied by X-ray photoelectron spectroscopy. The peak of Ba²⁺ 3d_3/2 is observed at the binding energy of 795.22 eV, while the peak of Ba²⁺ 3d_5/2 appears at the binding energy of 779.97 eV. Co²⁺ and Fe³⁺ contributions to octahedron and tetrahedron are calculated. The magnetic properties of the samples were studied using a vibrating sample magnetometer (VSM). We found that the saturation magnetization (Ms) of Ba_0.2Co_0.8Fe₂La_0.02O₄ nano-ferrite was higher compared to other samples, Which provides references for other investigators.