Structural and phase transition of α-Al2O3powders obtained by co-precipitation method

Aluminium oxide has been synthesized by co-precipitation technique at different annealing temperature. Powder XRD confirms the formation of α-Al2O3 with rhombohedral crystal structure having lattice constant a = 4.76 Å and b = 12.99 Å by the Scherer formula, the average crystallite size is estimated to be 66 nm. The scanning electron microscope results expose the fact that the α-Al2O3 nanomaterials are seemingly porous in nature and highly agglomerated. Chemical composition of aluminium oxide is confirmed by energy dispersive spectroscopy. The molecular functional group is confirmed by FTIR. Optical absorption of α-Al2O3 has been studied in the UV–vis region and its direct band gap is estimated to be 5.97 eV. This study involves the structural and phase transition of Al2O3 and also indicates that α-Al2O3 has considerable properties, deserving further investigation for the energetic materials with excellent properties for the possibility of using thin-layer α-Al2O3 as a thermo luminescence material.