Atomic layer deposition (ALD) was performed on quantities of multiwalled carbon nanotubes (MWCNTs) in a rotary reactor. Because of nucleation difficulties, Al2O3 ALD grew as nanospheres on the MWCNTs. After a NO2 nucleation treatment, Al2O3 ALD films grew conformally and noncovalently functionalized the surface of the MWCNT. This Al2O3 ALD film served as a platform for the growth of W ALD metal. The uncoated and ALD-coated MWCNTs were characterized with transmission electron microscopy and x-ray photoelectron spectroscopy. This study demonstrates that ALD can be performed on quantities of very high surface area MWCNT substrates.

Aluminum nitride (AlN) powders were produced in an aerosol flow reactor by direct nitridation of aluminum vapor with ammonia and nitrogen in flowing argon. In the presence of excess NH3, pure AlN powders were obtained from 1400 to 1873 K. These powders had higher specific surface areas than commercially available AlN powders. The effects of reactor temperature and gas flow rate on AlN purity, yield, and grain and crystallite size were investigated. The BET grain diameter of AlN increased as the process temperature increased, indicating sintering controlled particle formation and growth. Both the crystallite size and the BET grain size of pure AlN powders slightly decreased as ammonia flow rate was increased. Increasing temperature and flow rate increased the AlN yield.