Development of MgO–Y₂O₃ Composite Nanopowder by Pechini Sol–Gel Method: Effect of Synthesis Parameters on Morphology, Particle Size, and Phase Distribution

MgO–Y₂O₃ composite nanopowder was synthesized from Pechini method. Several experiments were conducted to examine the effects of the molar ratio of citric acid (CA) to transition metals (TM) calcination temperature and the pH value on the morphology, phases, and specific surface area of the samples. As-synthesized MgO–Y₂O₃ composite nanopowder were characterized by X-ray diffraction, field-emission scanning electron microscope (FESEM), transmission electron microscope, BET, thermal gravimetric–differential thermal analysis and Fourier transform infrared analysis. FESEM analysis revealed that the sample with the pH value of 1 and CA:TM = 10:1, had good homogeneity, and a spherical morphology with the particle size of 19.5 nm, while by increasing the pH up to 7 and 12, the particle size increased to 28.5 and 30.9 nm respectively. By increasing the mole ratio of CA to TM, the particle size and the specific surface area of MgO–Y₂O₃ composite nanopowder has reduced and by increasing the pH from 1 to 7 and 12, the particle size and the specific surface area of MgO–Y₂O₃ composite nanopowder has increased.