The effect of the Mg/Al ratio on the synthesis of MgAl2O4 nanoparticles by a reverse micelle process has been investigated in order to identify the phase composition in this system. Our study shows that the precursor ratio has significant effects on the structure and composition of the resulting nanoparticles. From the XRD analysis, a well-crystallized MgAl2O4 phase was formed at Mg/Al = 0.5 whereas at Mg/Al = 1, the crystallization of the nanoparticles was sluggish with MgAl2O4 and theta-Al2O3 phases co-existing. By optimizing the Mg/Al ratio in the micelle solution, the average particle size of MgAl2O4 nanoparticles is determined from SEM and TEM were found to be 18 and 14 nm, respectively. The FTIR spectra show the lower frequency hands are assigned to metal-oxygen bonds (M-O-M). The thermal behavior of the precursor powders was characterized by DTA-TGA analysis.

Keywords: Chemical synthesis; Ceramics: X-ray diffraction; Differential thermal analysis; Thermo gravimetric analysis; Transmission electron microscopy; Fourier transform infrared spectroscopy