Abstract
Aluminum and N2 (1 atm) react at 900−1100 °C to give AlN. The nitridation reactions of four types of starting Al powdernanocrystalline Al of two different origins, and 2-μm and 20-μm Al powders from commercial sourcesare described. All four Al powders undergo nitridation to give nanocrystalline AlN; however, only the nanocrystalline Al powders undergo nitridation completely at the low temperatures employed. The nanocrystalline AlN is formed in two principal particle morphologies, equiaxed nanoparticles and nanowhiskers, in relative amounts that depend on reaction conditions and the starting Al powders. Added AlCl3 is an effective promoter of nanowhisker growth. Either AlN morphology may be produced with a high selectivity; samples containing predominately equiaxed nanoparticles or predominately nanowhiskers are readily obtained. The results are consistent with a growth model in which the equiaxed AlN nanoparticles precipitate at or near the surface of coalesced liquid Al droplets, whereas the AlN nanowhiskers grow apart from the Al droplets in a vapor-transport process mediated by AlCl3 and Al subchloride intermediates.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
