Low temperature synthesis of nanocrystalline α-Al2O3 by a tartaric acid gel method

Nanocrystalline alumina was synthesized by a simple sol–gel method using aluminum nitrate in tartaric, oxalic and acetic acids mixed aqueous solutions. The alumina gel was successfully transferred to α-Al2O3 with this process after subsequent low temperature heat treatment. The prepared gel and powders were characterized by X-ray diffractometry (XRD), thermogravimetry-differential thermal analysis, scanning electron microscopy and transmission electron microscopy. The XRD analysis showed that the complete transformation from γ-Al2O3 nanocrystalline to α-Al2O3 (37 nm) prepared in tartaric acid was observed at 925 °C.