Structural, optical, and magnetic properties of Pr substituted Li–Ni Ferrites prepared by citrate -precursor method

The present research explores the structural, magnetic, and optical properties of Pr substituted Li–Ni ferrite, Li_0.5Ni_0.5Pr_xFe_2−xO₄ (where x = 0.01, 0.02, and 0.03) by low-cost citrate precursor method. The effect of Pr on physical, morphological, optical, multiferroic, and magnetic properties on Li–Ni ferrites are studied. Thermal analysis shows that the prepared material is stable after 500 °C. X-Ray diffraction revealed a single phase cubic spinal structure. Williamson–Hall plot was used to calculate the crystallite size, which was found to decrease from 30 to 15 nm with the addition of Pr³⁺ion. Surface morphology and size were studied using SEM and HRTEM, which show cuboids structure. The bond length was measured using FTIR and found to increase, while force constant decreases systematically with the addition of Pr³⁺ Indirect band gap was calculated using tauc plot and it was found to decrease from 2.28 to 2.22 eV with higher concentration of praseodymium ion. All the emissions peak in PL spectra lies in the visible range. Saturation Magnetization value was found in the range of 30.4–41.5 emu/g for Li_0.5Ni_0.5Pr_xFe_2−xO₄ ferrites. Coercivity value was found in the range of 148.58–192.60 Oe for Li-Ni-nano ferrite system, it also followed the decreasing trend having both least value i.e. saturation magnetization and coercivity at x = 0.03. This shows that the Pr-substituted material might be used in transformer cores due low coercivity and also in opto-electronic devices due to their improved optical and magnetic properties. The P-E loops measurement supports its functional property.