Polyol-mediated synthesis and characterization of magnesium–aluminum spinel nanoparticles

MgAl₂O₄ spinel nanoparticles were successfully synthesized using the polyol-mediated process. The study focused on the use of aluminum nitrate and magnesium acetate as precursor salts, with diethylene glycol as the solvent. The synthesis was conducted at three different temperatures: 150, 180, and 230 °C, followed by a subsequent calcination step. The dried samples consisted of a combination of magnesium oxalate and an unidentified amorphous or nanostructured phase. Upon calcination, all samples exhibited the desired MgAl₂O₄ spinel structure, along with a small amount of MgO. The FTIR spectra of the calcined samples confirmed the crystal structure of the MgAl₂O₄ phase as an inverse spinel. Scanning electron microscopy images revealed the quasi-spherical morphology of the nanoparticles, with particle sizes ranging from 70 to 120 nm for dried samples and 50 to 60 nm for calcined samples.