Enhanced room temperature ferromagnetism and versatile optical properties in MgFe2O4 spinel ferrite prepared under different calcination temperatures

Abstract

This study employs the sol-gel auto combustion technique fueled by diethanolamine (DEA) to synthesize nanocrystalline magnesium ferrite (MgFe₂O₄) powders. During the study, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible diffuse reflectance spectroscopy (UV-DRS), photoluminescence spectroscopy (PL), and vibrating sample magnetometry (VSM) were then used in order to determine how differing calcination temperatures influence the structure, chemical bonding, surface texture, morphology, optical, fluorescence, and magnetic properties of the resulting MgFe₂O₄ powders. The findings from the XRD and FT-IR analysis indicate that a single-phase spinel structure is formed in each of the MgFe₂O₄ samples. According to UV-DRS analysis, optimal calcination improved sample reflection levels in comparison to the visible and infrared spectral findings for the as-synthesized sample. The calcined samples exhibited bandgap energy (E_g) ranging from 2.11 eV to 2.14 eV, which was greater than the 2.02 eV of the as-synthesized sample. Examination of the PL spectra in the range of 380–700 nm revealed various light emission bands for the samples, which increased significantly in intensity at higher calcination temperatures. Furthermore, higher calcination temperatures also increased the magnetization of the MgFe₂O₄ spinel powders, while coercivity dropped significantly.