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Production Of Carbon Nanotubes By Chemical Vapor DepositionAyhan, Umut Baris 01 August 2004 (has links) (PDF)
ABSTRACT
PRODUCTION OF CARBON NANOTUBES BY
CHEMICAL VAPOR DEPOSITION
Ayhan, Umut BariS
M.S., Department of Chemical Engineering
Supervisor: Prof. Dr. Gü / ngö / r Gü / ndü / z
Co-Supervisor: Assoc. Prof. Dr. Burhanettin Ç / iç / ek
July 2004, 75 pages
Carbon nanotubes, which is one of the most attractive research subject for scientists, was synthesized by two different methods: Chemical vapor deposition (CVD), a known method for nanotube growth, and electron beam (e-beam), a new method which was used for the first time for the catalytic growth of carbon nanotubes.
In both of the methods, iron catalyst coated silica substrates were used for the carbon nanotube growth, that were prepared by the Sol-Gel technique using aqueous solution of Iron (III) nitrate and tetraethoxysilane. The catalytic substrates were then calcined at 450 ° / C under vacuum and iron was reduced at 500° / C under a flow of nitrogen and hydrogen.
In CVD method the decomposition of acetylene gas was achieved at 600 ° / C and 750 ° / C and the carbon was deposited on the iron catalysts for nanotube growth. However, in e-beam method the decomposition of acetylene was achieved by applying pulsed high voltage on the gas and the carbon deposition on the silica substrate were done.
The samples from both of the methods were characterized using transmission electron microscopy (TEM) and Raman spectroscopy techniques. TEM images and Raman spectra of the samples show that carbon nanotube growth has been achieved in both of the method. In TEM characterization, all nanotubes were found to be multi-walled carbon nanotubes (MWNT) and no single-walled carbon nanotubes (SWNT) were pictured. However, the Raman spectra show that there are also SWNTs in some of the samples.
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1002 |
高エネルギー反射光によるEB-PVD遮熱コーティングの残留応力分布の解析鈴木, 賢治, SUZUKI, Kenji, 松本, 一秀, MATSUMOTO, Kazuhide, 久保, 貴博, KUBO, Takahiro, 町屋, 修太郎, MACHIYA, Shutaro, 田中, 啓介, TANAKA, Keisuke, 秋庭, 義明, AKINIWA, Yoshiaki 11 1900 (has links)
No description available.
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GPS meteorology and the phenomenology of precipitable waterFoster, James H 12 1900 (has links)
Three studies of precipitable water using the Global Positioning System are presented. The first study finds that precipitable water in Hawaiʻi is best described by a lognormal distribution. The long-term average value of precipitable water declines exponentially with height, but the dispersion of precipitable water declines more linearly. The change in skewness of the distributions is also linear, although in this case it increases with elevation. The second and third studies use GPS meteorology to investigate a climatological and a meteorological event respectively. First, the effect of the 1997-1998 El Nino on precipitable water in the western tropical Pacific is studied and found to be consistent with a model relating the formation of an anomalous high-pressure ridge to the El Nino episode. Finally, the details of the precipitable water field for the Kaʻu Storm, November 2000 are examined. The results highlight the role of topography in controlling the location of convection, The observed correlation between the precipitable water and rainfall is used to generate estimates of rainfall based on GPS data, Comparing the GPS precipitable water estimates with those from a weather model indicates that the underestimates of rainfall produced by the weather model are probably due to correlated underestimates of precipitable water. / Thesis (Ph. D.)--University of Hawaii at Manoa, 2002. / Mode of access: World Wide Web. / Includes bibliographical references (leaves 62-66). / Electronic reproduction. / Also available by subscription via World Wide Web / ix, 66 leaves, bound ill. 29 cm
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1004 |
The single source chemical vapour deposition of alkaline earth metal oxide thin filmsHill, Matthew Roland, Chemistry, Faculty of Science, UNSW January 2006 (has links)
Metal oxide thin films are dynamic materials that have revolutionised the nature of semiconductor and electronic thin film devices. Recently, progress has stagnated in some aspects due to the increasingly complex deposition apparatus required, and the dearth of suitable precursor complexes of certain ???difficult??? metals. This thesis seeks to address both of these issues. The application of a precursor complex, Mg6(O2CNEt2)12 to the SSCVD of MgO thin films delivered the highest quality films ever reported with this technique. The resultant films were found to be of purely (111) orientation. Due to the nature of the precursor, the chemical reactions occurring at the surface during SSCVD growth result in a high growth rate, low flux environment and films of (111) orientation have been achieved without the amorphous underlayer. This finding has important implications for buffer layers in perovskite thin film devices. The unprecedented precursor chemistry has been used as a basis for the extremely high quality material produced, along with the unusual, yet beneficial structural morphology it possesses. A new range of barium complexes with single encapsulating ligands have been prepared for use in chemical vapour deposition (CVD) of BaTiO3 thin films. A novel pathway to an unprecedented class of barium carbamates is reported, and also new dianionic bis ??-ketoesterates and their barium, strontium, and calcium analogues were synthesised. High resolution mass spectrometry showed the barium bis ??-ketoesterate derivatives to be monomeric, and preliminary testing indicated some volatility in these species. Insights were gained into the likely successful pathways to building a volatile heterobimetallic precursor complex containing an alkaline earth metal. The knowledge of intimate mixing in heterobimetallic precursor complexes was extended by some novel chemistry to develop the first mixed Zn/Mg carbamato cluster complexes. These complexes were found to be excellent SSCVD precursors for ZnxMg1-xO thin films. Thin films were deposited with these precursors and exhibited a single preferred orientation, with a constant amount of magnesium throughout the bulk of the films. Investigation of the light emission properties of the films revealed significant improvements in the structural order commensurate with the incorporation of magnesium, and the formation of the ZnxMg1-xO alloy.
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Growth and characterization of CVD Ru and amorphous Ru-P alloy films for liner application in Cu interconnectShin, Jinhong, January 1900 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.
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1006 |
Growth and characterization of electrodeposited zinc sulphide and chemical vapour atomic layer deposited zinc oxide, sulphide, and oxysulphide thin films.Sanders, Brian Wayne. Kitai, A.H. Unknown Date (has links)
Thesis (Ph.D.)--McMaster University (Canada), 1991. / Source: Dissertation Abstracts International, Volume: 54-02, Section: B, page: 1040.
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Residual stress in gallium nitride films grown on silicon substrates by metalorganic chemical vapor depositionFu, Yankun. January 2000 (has links)
Thesis (M.S.)--Ohio University, June, 2000. / Title from PDF t.p.
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Fabrication and characterization of ZnO film by spray pyrolysis and ZnO polycrystalline sintered pellets doped with rear earth ionsAl-Ahmadi, Ahmad Aziz. January 2003 (has links)
Thesis (M.S.)--Ohio University, November, 2003. / Title from PDF t.p. Includes bibliographical references (leaves 58-62).
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1009 |
Microcrystalline silicon thin films prepared by hot-wire chemical vapour deposition /Mohamed, Eman. January 2004 (has links)
Thesis (Ph.D.)--Murdoch University, 2004. / Thesis submitted to the Division of Science and Engineering. Bibliography: 211-229.
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Corrosion protection of advanced surface coatings for decorative applicationsGopalakrishna, Jayashri Sham. January 2008 (has links)
Thesis (PhD) - Swinburne University of Technology, School of Engineering and Science, 2008. / A thesis submitted for the degree of Doctor of Philosophy, School of Engineering and Science, Swinburne University of Technology, 2008. Typescript. Includes bibliographical references (p. 189-204).
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