Crystalline alpha-alumina (α-A2O3) powders were prepared by using chemical co-precipitation method with different pH values. Prepared powders were fired at 1300°C in the air for 4 hours. Structural properties of the prepared powders were studied using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). XRD results confirm that the powders have the α-Al2O3 phase with the main peak (113) of rhombohedral(hexagonal) crystal structure, where the average crystallite size of particles of the prepared samples increasefrom (32-38)nm with increases of pH value. FTIR results indicate that the samples contain the molecular functional groups of (Al-O) bonds that appear in (AlO6) groupof the rhombohedral structure of α-Al2O3 with corundum structure which is built up only in this group, and this result supports the results of XRD. The SEM measurements results showed that the powders particles have apparent porosity, agglomerated size, and the size distribution of particles is mostly uniform where the particle size ranges from (93 to 189) nm.EDXwas used to confirm the chemical analysis of aluminium oxide powders and it showed that (Al) and (O) are the main components of alumina particles with no impurities, hence, confirmed the stoichiometric of the prepared alumina powder by the co-precipitation method.
