Effect of Ti Substitution on the Structural, Optical, and Magnetic Properties of Mn-Mg-Cu-Zn Ferrite Prepared by the Sol–Gel Route

In this study, Mn_0.15Mg_0.15Cu_0.2Zn_0.5Fe_2−xTi_xO₄ (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) nanoparticles were synthesized using the sol–gel auto-combustion method, and their structural, magnetic, and optical properties were investigated. Various characterization techniques were employed, including X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and magnetization measurements. The Rietveld refinement of XRD data confirmed that the samples exhibited a cubic spinel structure with space group Fd \(\overline{3 }\)m. This conclusion was further supported by the results of FTIR and Raman spectroscopy. Interestingly, the particle size of the samples increased with an increase in the tetravalent Ti⁴⁺ substitution. In contrast, the crystallite size and lattice parameter decreased. The optical properties of the samples were studied, revealing a maximum energy gap value in sample x = 0.3. Furthermore, the saturation magnetization decreased from 41.47 emu/g in sample x = 0.0 to 7.36 emu/g in sample x = 0.6. Overall, this comprehensive investigation demonstrated the tunable properties of Mn_0.15Mg_0.15Cu_0.2Zn_0.5Fe_2−xTi_xO₄ nanoparticles and highlighted their potential for various applications, particularly in the fields of magnetism and optoelectronics.