Gas-phase synthesis of AlN powders from AlCl₃-NH₃-N₂

Abstract

Aluminium nitride powders were synthesized by the gas-phase reaction of AlCl₃-NH₃-N₂ system. The yield of AlN powders from AlCl₃ and their crystallinity increased as the reaction temperature and the mole ratio of NH₃/AlCl₃ were increased. AlN powders were also formed outside the reactor and their crystallinity was amorphous. The yield of AlN powders was as high as 80% when the reactor temperature was 1000 °C and the mole ratio of NH₃/AlCl₃ was 8. Most of the HCl by-product was recovered as NH₄Cl outside the reactor. Powder characteristics, such as shape, size distribution and crystallinity, were also studied.