Synthesis of Magnesia-Spinel Nanocomposites from Soluble Salts as Precursors

Nanocomposites of magnesia-spinel (MgO/MgAl2O4) were successfully prepared using soluble salts of aluminum and magnesium sulphates as the precursors and an organic compound of sucrose as a masking compound through sucrose-precursors process. Calcination treatment was performed at 800 degrees C, 900 degrees C, and 1000 degrees C. Spinel MgAl2O4 phase was found to transform and to crystallize at 800 degrees C in low and weak peaks. However, nanocomposites of magnesia-spinel were completely formed at 1000 degrees C consisting of spinel magnesium aluminates and periclase phases. The quantitative results based on X-rays diffraction analysis show that MgAl2O4 and periclase phases having crystal sizes of about 16-18 nm and 37-38 nm, respectively. In addition, the mineral composition of the nanocomposites consists of 79.9 % spinel phase and 20.1 % periclase phase. The average grain sizes of the nanocomposites of magnesia-spinel powder were less than 100 nm, as given by SEM.