TITLE:
Phase Transition Behavior of Nanocrystalline Al2O3 Powders
AUTHORS:
Balaraman Sathyaseelan, Iruson Baskaran, Kandasamy Sivakumar
KEYWORDS:
Nanocrystalline Al2O3; Phase Transitions; γ-Al2O3; α-Al2O3; Differential Scanning Calorimetry (DSC); Electron Microscopy (TEM and SEM)
JOURNAL NAME:
Soft Nanoscience Letters,
Vol.3 No.4,
October
11,
2013
ABSTRACT: Alumina (Al2O3) has been synthesized through combustion synthesis (CS) technique. The calcined products were characterized using X-ray diffractional analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermo-gravimetric analysis (TGA). TG-DTA results reveal the various stages involved in transition from γ-phase to α-Al2O3 phase. The first phase γ-Al2O3 was presented in the temperature range from 600°C-875°C as deduced from the XRD patterns with cubic crystal structure. The second stage occurs in the temperature range from 900°C-1000°C. In the final step, above 1000°C, the aluminium oxide appears completely as α-Al2O3, showing high crystallinity. The particle sizes are closely related to γ- to α-Al2O3 phase transition.