Effects of catalyst pretreatment for carbon nanotube growth
Name
301368410-MIT.pdf
Description
Full printable version
Size
7.39 MB
Format
Adobe PDF
Checksum (MD5)
79e22298571c77683fdb66fa275d3d13
Author(s)
Morgan, Caitlin D
Advisor(s)
Carl V. Thompson.
Alternative Title
Effects of catalyst pretreatment for CNT growth
Date Issued
2007
Publisher
Massachusetts Institute of Technology
Abstract
The effects of pretreatment of iron catalyst for carbon nanotube (CNT) growth was studied. CNTs were grown on Fe/A1203 (1/10 nm) thin-film catalyst deposited on silicon substrates via exposure to C2H4 in a thermal chemical vapor deposition (CVD) furnace. During CVD, the sample was exposed to a carrier gas (Argon) for the 35-minute temperature ramp, and 15-minute anneal, then to a mix of carrier gas and ethylene for a 15-minute growth stage. Experiments were performed varying the amount of oxygen contaminant in the carrier gas, and the time of hydrogen introduction. Samples were characterized via atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the later hydrogen was introduced, the higher the catalyst density and the taller the CNT carpet. The catalyst efficiency was also shown to increase with later hydrogen introduction. No clear trend was observed between the amount of oxygen in the carrier gas and the height of CNT growth. Data points to the model of catalyst coarsening being crucial to the nucleation and growth of CNTs and the parameters of CNTs grown. Variations in trends are discussed.
Description
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.
Includes bibliographical references (leaves 36-37).
Subjects
Materials Science and Engineering.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
M.I.T. theses are protected by
copyright. They may be viewed from this source for any purpose, but
reproduction or distribution in any format is prohibited without written
permission. See provided URL for inquiries about permission.
copyright. They may be viewed from this source for any purpose, but
reproduction or distribution in any format is prohibited without written
permission. See provided URL for inquiries about permission.
Persistent DSpace Link
