Formation and characterization of cubic A1N crystalline in a carbothermal reduction reaction

摘要

Cubic aluminum nitride has been obtained in carbothermal reduction reaction at 1700-1800 deg C under a flowing nitrogen stream. The as-synthesized products were characterized by XRD, SAD and IR spectrum. The results indicated the product was consisted of wurtzite hexagonal A1N, cubic A1N and corundum. It is speculated that the nucleation and growth of cubic A1N result from the transition of cubic A1ON, since intermediate A1ON in carbothermal reduction has the same cubic symmetry as cubic A1N. Cubic A1N are unstable metastable phase and are easily transformed into stable hexagonal A1N via crystalline transition with increasing reaction temperature or reaction time. The formation mechanism of cubic A1N is also discussed.