Synthesis and characterization of nano-scale aluminum nitride produced from vapor phase

Nano-scale AlN particles were synthesized from the vapor phase using ammonia and aluminum chloride vapor as reactants. The apparatus consists of vaporization system, ammonia distributor, tubular synthesis reactor and powder collection system. The aluminum nitride nucleates and grows along the reactor length. The AlN powder produced was collected and chemically and physically characterized. For microstructural and microchemical characterization, X-ray diffractograms taken from the powder have shown the presence of primarily AlN, with traces of Al2O3, while the deposit removed from the reactor wall has displayed solely AlN. Van der Waalʹs forces and the tendency for surface energy minimization cause the particles to hold together and what the SEM, in fact, reveals are small particle aggregates. TEM observations, however, confirm the nano-scale nature of such particles with an average particle size of 30 nm. HREM imaging of individual particles indicates that most of them are single crystals, since lattice fringes run continuously along the entire length of the particle.