Laser-driven synthesis of Al₂O₃ based ceramic powders from gaseous precursors has been accurately investigated. Different concentrations of the reactant gaseous precursors are shown to influence both the process yield and the synthesized powder composition. Depending on the relative concentration of TMA : Al(CH₃)₃ and N₂O, the process leads either to the formation of nanocrystalline γ-Al₂O₃ with large free carbon contamination and traces of the Al₃O₃N phase or to the formation of a mixed γ-Al₂O₃, Al₂OC compound. The different reaction paths have been attributed to the intermediate formation of aluminum carbide. Particular attention has been paid to the gaseous reaction products to correctly interpret the source of carbon contamination observed in the formed powders. Calcining at moderate (900°C) and high (1400°C) temperatures induces nanosized γ-Al₂O₃ powder and the γ→α-Al₂O₃ transition with particle coalescence and growth.

Cited By (since 1996): 12Export Date: 1 September 2010Source: Scopus