Pure and Al doped ZnO nano powders X-ray diffraction and Fourier transform infrared analysis

ZnO nano powders were prepared by sol-gel technique using zinc acetate dihydrate and acetic acid monohydrate diluted respectively in absolute ethanol and distilled water. Aluminum doping is made by mixing Al₂O₃ powder with that obtained in the synthesis of ZnO before crystallization annealing. The crystallization annealing is at the same time that doping. Two methods of characterizations that are the x-ray diffraction and infrared spectroscopy by Fourier transform have been used to characterize these powders. The effects of citric acid concentration, the temperature of crystallization and the doping on the crystalline structure have been systematically examined. Both powders doped than those pure are nano crystal. Large concentrations of citric acid and doping are responsible for the existence of compressive stresses in the crystallites constituting the powders. The doped powders seem to be a nano composite ZnO/ZnAl₂O₄.