NASA Scientific and Technical Aerospace Reports

carbocation is attributed to a greatly reduced O3 binding energy. The ions listed above do not undergo two-body reactions with
02, k \h 5 x 10(exp -13)cu cm/s, despite the availability of reaction channels with exothermicities of several hundred kilojoules
per mole. Ab initio calculations at the B3LYP/6-31G(d) level of theory indicate that the 02 reaction systems form weak
complexes with large C-O bond distances (repulsive at smaller distances) on the lowest energy triplet potential energy surface.
Access to the singlet surface is required for bond formation; however, this surface is not accessible at thermal energies.
DTIC
Alkyl Compounds; Cations; Ions; Oxidation; Oxygen; Ozone; Vapor Phases
20040120863 NASA Glenn Research Center, Cleveland, OH, USA
Growth of Multi-Walled Carbon Nanotubes by Injection CVD Using Cyclopentadienyliron Dicarbonyl Dimer and
Cyclooctatetraene Iron Tricarbonyl
Harris, Jerry D.; Raffaelle, Ryne P.; Gennett, Thomas; Landi, Brian J.; Hepp, Aloysius F.; [2004]; 20 pp.; In English
Contract(s)/Grant(s): NCC3-817; NCC3-869; NAG3-2484; WBS 22-319-20-A1; Copyright; Avail: CASI; A03, Hardcopy
Preferential oriented multiwalled carbon nanotubes were prepared by the injection chemical vapor deposition (CVD)
method using either cyclopentadienyliron dicarbonyl dimer or cycloctatetraene iron tricarbonyl as the iron catalyst source. The
catalyst precursors were dissolved in toluene as the carrier solvent for the injections. The concentration of the catalyst was
found to influence both the growth of the nanotubes as well as the amount of iron in the deposited material. As deposited the
multiwalled carbon nanotubes contained as little as 2.8% iron by weight. The material was deposited onto tantalum foil and
fused silica substrates. The nanotubes were characterized by scanning electron microscopy, transmission electron microscopy,
Raman spectroscopy and thermogravimetric analysis. This synthetic route provides a simple and scalable method to deposit
MWNTs with a low defect density, low metal content and preferred orientation.
Derived from text
Carbon Nanotubes; Catalysts; Nanostructure Growth; Vapor Deposition; Nanotechnology
20040120865 NASA Glenn Research Center, Cleveland, OH, USA
CuInS2 Films Deposited by Aerosol-Assisted Chemical Vapor Deposition Using Ternary Single-Source Precursors
Jin, Michael H.-C.; Banger, Kulbinder K.; Harris, Jerry D.; Hepp, Aloysius F.; [2004]; 25 pp.; In English
Contract(s)/Grant(s): NCC3-947; WBS 22-319-20-A1; Copyright; Avail: CASI; A03, Hardcopy
Polycrystalline CuInS2 films were deposited by aerosol-assisted chemical vapor deposition using both solid and liquid
ternary single-source precursors (SSPs) prepared in-house. Films with either (112) or (204/220) preferred orientation were
obtained, and compositional analysis showed that (112)-oriented films contained more copper than (204/220)-oriented films.
Using X-ray diffraction, the signature of chalcopyrite structure was often confirmed for (112)-oriented films. The preferred
orientation of the film is likely related to the decomposition and reaction kinetics associated with the molecular structure of
the precursors at the substrate. Interestingly, the (204/220)-oriented films were always accompanied by a secondary phase,
which was identified as an unknown In-rich compound from the results of post-growth annealing, etching experiments, and
Raman spectroscopic data. By increasing Cu to In ratio in the film, (112)-oriented films were obtained with a maximum grain
size of about 0.5 micrometers, and their X-ray diffractions did not show any observable signature of the In secondary phase.
Electrical and optical properties of all the films grown were characterized. They all showed p-type conduction with an
electrical resistivity between 0.1 omega cm and 30 omega cm, and an optical band gap of 1.46eV +/- 0.02, as deposited. The
material properties of deposited films revealed this methodology of using SSPs for fabricating chalcopyrite-based solar cells
to be highly promising.
Author
Photovoltaic Effect; Copper Sulfides; Indium Sulfides; Polycrystals; Vapor Deposition; Electrical Resistivity; Aerosols; Metal
Films
20040120926 Lawrence Livermore National Lab., Livermore, CA, USA, California Univ., Lawrence Berkeley National
Lab., Berkeley, CA, USA
Effect of Processing Conditions on the Physical and Electrochemical Properties of Carbon Aerogel Composites
Tran, T. D.; Lenz, D.; Kinoshita, K.; Droege, M.; 2003; In English
Report No.(s): DE2003-15005277; UCRL-JC-141288; No Copyright; Avail: National Technical Information Service (NTIS)
The carbon aerogel/carbon paper composites have physical properties similar to those of monolithic carbon aerogels but
do not require supercritical extraction during fabrication. The resorcinol-formaldehyde based carbon aerogel phase is
intertwined between the fibers of a commercial carbon paper. The resulting composites have variable densities (0.4-0.6 g/cc),
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