Дисертації з теми "Ore deposition"
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Spencer, Edward. "The transport and deposition of molybdenum in porphyry ore systems." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/27402.
Повний текст джерелаArchibald, Sandy M. "The role of vapour in the transport and deposition of metals in ore-forming systems /." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82821.
Повний текст джерелаCalculations based on the solubility data indicate an economic high-sulphidation Au deposit (e.g., Nansatsu, Japan; 36 tonnes) could form in ~30,000 years, whereas a porphyry copper deposit (e.g., 50 million tonnes at 0.5% Cu) could form in as little as ~20,500 years, assuming transport only in the vapour phase.
Precious- and base-metal-rich composite scales, containing up to 111 ppm Au and 628 ppm Ag, occur in surface pipes at the Momotombo geothermal field, Nicaragua. Polysulphide scale fragments, comprising chalcopyrite, sphalerite, galena, electrum and hessite grains in a matrix of amorphous silica, formed as a result of cooling and ligand loss induced by boiling, during fluid ascent in well MT-36. Secondary bornite, stromeyerite and chalcocite/digenite replaced chalcopyrite through the addition of Cu and Ag and an increase in fO2 . A drop in pH due to well closure resulted in replacement of primary and secondary sulphides by tetrahedrite.
Reaction-path modelling using the program CHILLER simulates deposition of minerals from the reconstructed deep geothermal fluid, at temperature intervals (depths) along excess enthalpy and isoenthalpic boiling paths. These simulations accurately reproduce the paragenetic sequence of base- and precious-metal mineralization in the scales. The modelling indicates excess enthalpy boiling results in metal precipitation at greater depths than would be expected for isoenthalpic boiling, and that at Momotombo this occurs through the destabilisation of bisulphide complexes in response to loss of CO2 and H2 S during phase separation.
Törmänen, T. (Tuomo). "Ore mineralogy, geochemistry, and formation of the sediment-hosted sea floor massive sulfide deposits at Escanaba Trough, NE Pacific, with emphasis on the transport and deposition of gold." Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514276264.
Повний текст джерелаGapara, Cornwell Sine. "A review of the deposition of iron-formation and genesis of the related iron ore deposits as a guide to exploration for Precambrian iron ore deposits in southern Africa." Thesis, Rhodes University, 1993. http://hdl.handle.net/10962/d1005610.
Повний текст джерелаBouse, Robin Marie. "Lead isotopic compositions of ore deposition and their host rocks in Arizona: Implications for the crustal inheritance of metals." Diss., The University of Arizona, 1995. http://hdl.handle.net/10150/187411.
Повний текст джерелаBao, Zhiwei. "Geochemistry of the sediment-hosted disseminated gold deposits in Southwestern Guizhou Province, China." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2001. http://theses.uqac.ca.
Повний текст джерелаPolteau, Stéphane. "The early proterozoic Makganyene glacial event in South Africa : its implication in sequence stratigraphy interpretations, paleoenvironmental conditions and iron and manganese ore deposition." Thesis, Rhodes University, 2005. http://hdl.handle.net/10962/d1007612.
Повний текст джерелаLaurila, Tea Elisa. "The Metalliferous Sediments of the Atlantis II Deep (Red Sea)." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32229.
Повний текст джерелаNilsson, Erik A. A. "Degradation Mechanisms of Heat Resistant Steel at Elevated Temperatures : In an Iron Ore Pelletizing Industry." Doctoral thesis, Luleå tekniska universitet, Materialvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-62162.
Повний текст джерелаStalder, Marcel. "Petrology and mineral chemistry of sulphide ores and associated metalliferous rocks of the Gamsberg Zn-Pb deposit, South Africa : implications for ore genesis and mineral exploration." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16072.
Повний текст джерелаENGLISH ABSTRACT: The Gamsberg Zn-Pb deposit is a metamorphosed and multiply deformed sediment-hosted base metal deposit in the central Namaqua Province of South Africa. The deposit is hosted by the Bushmanland Group, a late Palaeoproterozoic (2000-1600 Ma) supracrustal succession of quartzite, metapelitic schist and interbedded metavolcanic rocks. Mineralisation occurs within the central part of the Gams Formation, a heterogeneous sequence of metamorphosed metalliferous sediments and fine-grained organic-rich shales. The ore horizon is subdivided into a lower unit of metapelite-hosted ore, an intermediate layer of phosphorite-hosted ore, and an upper unit of banded garnet-apatite ore. The ore body is enveloped by unmineralised silicate-, carbonate- and oxide-facies metalliferous rocks, which originally represented mixtures of Fe-Mn-rich hydrothermal precipitates, authigenic carbonate, and variable concentrations of detrital material. Based on mineralogical and geochemical characteristics, the metalliferous host rocks are subdivided into iron formations, coticules, Fe-Mn silicates, impure marbles and barite/Ba-rich quartzite. Minerals of the Gams Formation mostly represent solid solution between the Fe and Mn end-members of garnet, pyroxene, pyroxenoid, amphibole, olivine, spinel and ilmenite. Calcium-rich rock types are a typical feature and characterized by the occurrence of manganoan calcite, clinopyroxene, andradite-rich garnet and titanite. A successive increase in the (Mn+Ca):Fe value of rocks and minerals is evident with increasing distance from the ore horizon. Amphibole is restricted to Fe-rich ore-bearing assemblages, whereas orthopyroxene, clinopyroxene, Fe-rich pyroxenoid and olivine are present in intermediate assemblages, and Mn-rich rhodonite and pyroxmangite in the most manganiferous assemblages. These variations are mimicked by an increase in the Mn:Fe value of coexisting garnet and ilmenite group minerals with increasing distance from ore. LA-ICP-MS analyses have been used to constrain the REE patterns of garnet and apatite. In the ore-body, these minerals display a positive Eu anomaly, which is interpreted to reflect a distinct hydrothermal signature. In contrast, garnet and apatite in unmineralised metalliferous rocks display nil or a negative Eu anomaly. Primary features of the Gams Formation, such as REE patterns, the banded nature of garnet-apatite ore, the presence of diagenetic apatite nodules, and the distribution of the redox-sensitive elements Ba and Mn have been used to constrain palaeo-environmental conditions. The results indicate that metapelitehosted ore has been deposited in a stratified ocean that was characterised by anoxic bottom waters and precipitation of Fe and Zn sulphides into organic matter-rich shales. These rocks were superceded by phosphorite-hosted ore, garnet-apatite ore and metalliferous host rocks that developed in a suboxic to oxic environment. The large size of the deposit, the internal lamination of the ores and the predominance of sphalerite and barite are consistent with a vent-distal setting and precipitation of the ore-forming constituents from dense and reduced hydrothermal fluids, which originated due to reactivation of dormant growth faults. Collectively, the geological evidence indicates that Gamsberg is bridging the gap betweenthe SEDEX and BHT classifications. The relationships demonstrate that differences between these two classes of sediment-hosted Zn-Pb deposits are predominantly related to environmental conditions within localised third order basins and not to fundamental differences in ore-forming processes.
AFRIKAANSE OPSOMMING: Die Gamsberg Zn-Pb afsetting is ‘n meerfasig vervormde en gemetamorfiseerde sedimentgesetelde onedel metaal afsetting in die sentrale Namakwa Provinsie van Suid Afrika. Die afsetting word geherberg deur die Boesmanland Groep, ‘n laat Paleoproterosoïse (2000 – 1600 Ma) bokors-opeenvolging van kwartsiet, metapelitiese skis en tussengelaagde metavulkaniese gesteente. Mineralisasie word gevind in the sentrale deel van die Gams Formasie. Die Gams Formasie is ‘n heterogene opeenvolging van gemetamorfiseerde metaalhoudende sediment en fynkorrelrige organiese skalie. Die erts horison word onderverdeel in ‘n onderste laag van metapeliet-gesetelde erts, n sentrale laag van fosforiet-gesetelde erts, en ‘n boonste laag van gebande granaat-apatiet erts. Die erts-liggaam word omhuls deur ongemineraliseerde silikaat-, karbonaat- en oksied-fasies metal-ryke rotse. Hierdie gesteentes word geinterpreteer as oorspronklike mengsels van Fe-Mn-ryke hidrotermale partikels, outigeniese karbonaat, en verskeie hoeveelhede detritale materiaal. Gebaseer op mineralogiese en geochemiese kenmerke word hierdie rotse onderverdeel in ysterformasies, „coticules“, Fe-Mn silikate, onsuiwer marmer en barite/Ba-ryke kwartsiet. Minerale van die Gams Formasie form meestal soliede oplossingsreekse tussen die Fe en Mn endlede van granaat, pirokseen, piroksenoid, amfibool, olivien, spinel en ilmeniet. Kalsium-ryke rots tipes is ‘n tipiese kenmerk van die Gams Formasie en word gekenmerk deur mangaan-ryke kalsiet, klinopirokseen, andradiet-ryke granaat en sfeen. Daar word ‘n stapsgewyse vergroting van die (Mn+Ca):Fe verhouding in gesteentes en minerale gevind met toeneemende afstand van die erts horison. Amfibool is beperk tot Fe-ryke ertsdraende gesteentes, ortopirokseen, klinopirokseen, Fe-ryke piroksenoid en olivien tot intermediêre gesteentes, en Mn-ryke rodoniet en piroksmangiet tot Mn-ryke gesteentes. Hierdie variasies gaan gepaard met vergroting van die Mn:Fe verhouding in granaat en ilmeniet-groep minerale met toeneemende afstand van die erts. LA-ICP-MS analises was gebruik om die skaars-aarde element patrone van granaat en apatiet te bepaal. In die erts-liggaam wys hierdie minerale ‘n positiewe Eu anomalie, wat geinterpreteerd word as ‘n hidrotermale kenmerk. In ongemineraliseerde gasheer gesteentes wys granaat en apatiet geen of ‘n negatiewe Eu anomalie. Primêre kenmerke van die Gams Formasie, soos skaars-aarde patrone, the gebande voorkoms van granaat-apatiet erts, die teenwoordigheid van diagenetiese apatiet knolle, en die verspreiding van die redox-sensitiewe elemente Ba en Mn, was gebruik om afleidings oor die paleo-omgewing te maak. Die resultate het gewys dat metapeliet-gesetelde erts afgeset was onder anoksiese bodem water deur presipitasie van Fe en Zn sulfiedes in organiese skalie. Hierdie erts gaan oor in fosforiet-gesetelde erts, granaat-apatiet erts en metaal-ryke gasheer gesteente wat in ‘n suboksiese tot oksiese omgewing ontstaan het. Die grootte van die afsetting, die interne gelaagdheid van die erts, asook die teenwoordigheid van sfaleriet en bariet dui op ‘n distale omgewing relatief tot die hidrotermale bron en presipitasie van die ertsuit digte en gereduseerde hidrotermale vloeistowwe, wat ontstaan het deur die heraktiveering van rustende groeiverskuiwings. Gesaamentlik bewys die geologiese kenmerke van Gamsberg dat gemetamorfiseerde SEDEX en Broken Hill-tipe mineralisasie binne die perke van ‘n enkele afsetting kan voorkom. Die geologiese verhoudings dui aan dat verskille tussen hierdie twee tipes van sedimentgesetelde afsettings meestal veroorsaak word deur omgewings-toestande binne in gelokaliseerde derde orde komme en nie deur fundamentele verskille in ertsvormende prosesse nie.
Daglioglu, Yasar Mehmet. "A review of sediment-hosted gold deposits of the world with special emphasis on recent discoveries outside the U.S.A." Thesis, Rhodes University, 1996. http://hdl.handle.net/10962/d1005609.
Повний текст джерелаFu, Qilin. "An investigation into Plasma Vapor Deposition Aided Chemical Vapor Deposition : A PVD aided CVD process for depositing Nitrogenatoms mixed in Carbon Diamond-Like-Structure is investigated and one such layer is formed with this method." Thesis, KTH, Industriell produktion, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-50056.
Повний текст джерелаGuo, Li. "Synthesis of one-dimensional boron related nanostructures by chemical vapor deposition." Cincinnati, Ohio : University of Cincinnati, 2008. http://www.ohiolink.edu/etd/view.cgi?ucin1206412343.
Повний текст джерелаCommittee/Advisors: Raj N. Singh PhD (Committee Chair), Relva C. Buchanan PhD (Committee Member), Rodney Roseman PhD (Committee Member), Donglu Shi PhD (Committee Member). Title from electronic thesis title page (viewed Sep.3, 2008). Keywords: Boron nitride nanotube (BNNT); boron nanowire (BNW); chemical vapor deposition (CVD). Includes abstract. Includes bibliographical references.
Li, Ning. "Depositional controls and genesis of the Jinding sandstone-hosted Zn-Pb deposit, Yunnan Province, Southwest China /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
Повний текст джерелаVita. One folded ill. in pocket. Includes bibliographical references (leaves 222-235). Available also in a digital version from Dissertation Abstracts.
Zhou, Zhengzhi. "Synthesis of one-dimensional nanostructure materials." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29703.
Повний текст джерелаCommittee Chair: Deng,Yulin; Committee Member: Hsieh, Jeffery S.; Committee Member: Nair, Sankar; Committee Member: Singh, Preet; Committee Member: Yao, Donggang. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Sechrist, Zachary Aspen. "One-dimensional and three-dimensional photonic crystals created using atomic layer deposition." Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3239418.
Повний текст джерелаAnderson, Iain Kerr. "Ore depositional processes in the formation of the Navan zinc/lead deposit, Co. Meath, Ireland." Thesis, University of Strathclyde, 1990. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=23503.
Повний текст джерелаRicci, Giovanni. "Organic matter deposition/resuspension in a one-dimensional physical-biogeochemical model. A modelling study." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10595/.
Повний текст джерелаTsikos, Harilaos. "Petrographic and geochemical constraints on the origin and post-depositional history of the Hotazel iron-manganese deposits, Kalahari Manganese Field, South Africa." Thesis, Rhodes University, 2000. http://hdl.handle.net/10962/d1005599.
Повний текст джерелаYu, Kyle Kai-Hung. "Interfacial Electrochemistry of Copper and Spectro-Electrochemical Characterization of Oxygen Reduction Reaction." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc103416/.
Повний текст джерелаCheng, An-jen Park Minseo Tzeng Y. "One dimensional zinc oxide nanostructures for optoelectronics applications solar cells and photodiodes /." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Electrical_and_Computer_Engineering/Dissertation/Cheng_An-jen_33.pdf.
Повний текст джерелаDuff, Shamus. "Ore Types of the Auriferous Lalor VMS Deposit, Snow Lake, Manitoba: Implications for Genesis and Post Depositional Processes." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34586.
Повний текст джерелаBarzegar, HamidReza. "Synthesis and Characterization of Carbon Based One-Dimensional Structures : Tuning Physical and Chemical Properties." Doctoral thesis, Umeå universitet, Institutionen för fysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-97551.
Повний текст джерелаStone, Michelle Susanne. "Depositional history and mineralisation of tertiary channel iron deposits at Yandi, Eastern Pilbara, Australia." University of Western Australia. School of Earth and Geographical Sciences, 2005. http://theses.library.uwa.edu.au/adt-WU2005.0082.
Повний текст джерелаGrimm, Daniel. "A combined experimental and theoretical approach towards the understanding of transport in one-dimensional molecular nanostructures." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1218037048209-51309.
Повний текст джерелаGao, Puxian. "Piezoelectric Nanostructures of Zinc Oxide: Synthesis, Characterization and Devices." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7564.
Повний текст джерелаBergh, Eugene W. "A one-year, postfire record of element deposition and cycling in the Kogelberg sandstone fynbos mountain ecosystem of the Western Cape, South Africa by Eugene W. Bergh." Master's thesis, University of Cape Town, 2012. http://hdl.handle.net/11427/10101.
Повний текст джерелаIncludes bibliographical references.
Fire is a critical component of the fynbos ecosystem and this study documents the macronutrient (C1, Na, So4, Mg, Ca and K) dynamics of the fynbos for one year following a major fire event on 3 June 2010. Chloride and sodium in rainwater and stream water were found to be primarily derived from a marine aerosol source.
Gaona, Narvaez Tatiana. "Lower Aptian Comparative Stratigraphy of the Basco-Cantabrian Region (Spain) and Eastern Cordillera (Colombia): implications for local factors in the depositional record of Oceanic Anoxic Event 1a (OAE-1a)." FIU Digital Commons, 2013. http://digitalcommons.fiu.edu/etd/952.
Повний текст джерелаHuber, Rupert Verfasser], Dirk [Akademischer Betreuer] Grundler, and Paolo [Akademischer Betreuer] [Lugli. "Control of Spin Waves on the Nanoscale in One-Dimensional Magnonic Crystals and Atomic Layer Deposition of Metallic Ferromagnets for Second Generation of Nanomaterials / Rupert Huber. Gutachter: Dirk Grundler ; Paolo Lugli. Betreuer: Dirk Grundler." München : Universitätsbibliothek der TU München, 2013. http://d-nb.info/1047185474/34.
Повний текст джерелаGestraud, Cecilia. "Synthèse, fonctionnalisation et assemblage de nanodisques d'argent." Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0112.
Повний текст джерелаSilver nanoparticles, used extensively in catalysis, optics and electronics, are now emerging in new applications such as imaging, photonics or chemical and biochemical detection. Among these applications, some require particular morphologies such as rods or disks (conductive films, enhanced Raman spectroscopy) while others mainly involve a large specific surface area such as in heterogeneous catalysis. Anisotropic metal nanoparticles are traditionally produced in two stages, separating the formation of seeds and their growth, in order to better control their morphology. However, the two-stage synthesis makes the transfer on industrial scale difficult because of the long incubation time and the washing steps required. In this context, we decided to focus on the synthesis of anisotropic nanoparticles, in particular silver nanodisks, as well as their assembly in solution and on surfaces. In our work, we adopted an approach that allows to carry out the two stages of the formation of silver nanodisks in the same reaction medium. The principle is based on the use of two reducers, one weak and one strong, with different kinetic reduction rates, allowing the control of anisotropy. This method is simple and fast but requires good control of the experimental parameters. The time between the addition of the two reducers determines the morphology of the formed objects. There is actually an optimal range for this time, which depends particularly on the temperature of the synthesis. In order to vary the optical properties of these nanodisks, different strategies can be considered. We chose to form assemblies both in solution and on surfaces by different deposition techniques. The adsorption of bifunctional organic molecules can provoke the formation of assemblies in solution: one function has an affinity with silver and the other interacts with the free functions of the other nanoparticles through hydrogen or electrostatic bonds for example. Assemblies can also be made on surfaces. We have been working on original deposition method, which allow an oriented assembly of nanodisks through electrostatic forces.We have demonstrated that these assemblies are good candidates for developing micro-structured SERS substrates
Wurst, A. T. "Analyses of late stage, Mesoproterozoic, syn and post tectonic, magmatic events in the Moonta Sub-domain: Implications for Cu-Au mineralisation in the "Copper Triangle" of South Australia." Thesis, 1994. http://hdl.handle.net/2440/88299.
Повний текст джерелаThe Moonta-Wallaroo area has been of economic, historical and scientific importance in South Australia's history for over 130 years. The nature of mineralisation in the area has long been a point of conjecture. This study looks at the nature of ore deposition and specifically its relationship to granitoids and pegmatites in the Moonta Subdomain. Using various analytical techniques the study has shown that granitoids in the region have distinctly different petrological, textural, structural, geochemical and isotopic characteristics. Two main granitoids were·recognised as the Tickera Granite and the Arthurton Granite. Geochemical studies suggest that magmatism in the Moonta Subdomain was a continuous process in the Mesoproterozoic. The older Tickera Granite, displays syn-collisional, more I-type characteristics and syn-collisional S-type characteristics (represented by a monzonite and a tonalite respectively). The younger Arthurton Granite shows A-type, anorogenic characteristics. A temporal shift from syn-collisional to anorogenic granites suggests a tectonic control on magma generation and emplacement during this period. Trace element characteristics of the Arthurton Granite are homogeneous over a wide spatial range, is suggesting that it may be part of an extensive batholith. Geochemistry of pegmatites implies that they were late stage fractionation products, related to these granite intrusions. A study of the Tickera Granite (Point Riley-Nth Beach) revealed a dominant structural fabric which suggested the granite was intruded into a tectonic regime in which shearing was prominent. Sediments intruded by the granite suggested deposition in a shallow intracratonic rift setting, followed by polyphase deformation during orogenic activity and subsequent shearing possibly related to the enigmatic Wartakan Event. Isotopic studies highlighted differences in the petrogenetic source regions of the Tickera Granite and the Arthurton Granite. The Tickera Granite (represented by monzonite) displayed more mantle like characteristics while the Arthurton Granite (represented by granite from Arthurton and adamellite from Moonta) displayed more crustal features, highlighting its A-type nature. Studies also showed that a pegmatite from the Wheal Hughes was most like the later of these two granites. Tourmaline studies of Wheal Hughes samples implicated derivation from a metapelite and calcsilicate precursor, a common feature of most tourmaline studied in the area. This may indicate remobilisation of boron rich fluids and metals from these sediments The close association of tourmaline with the ore in the Moonta Mines region implied a common source region. A tectonic setting and model for ore deposition is proposed on the basis of the study findings. The model proposed the remobilisation of metals which were initially deposited in a ensialic rift type environment (common to other Palaeoproterozoic metalliferous terrains) by the intrusion of the Tickera Granite, during regional shearing. And further concentration of metals by subsequent intrusions of the Arthurton Granite batholith.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Earth and Environmental Sciences, 1994
Gutierrez, Gay Nell 1955. "Controls on ore deposition in the Lamotte Sandstone, Goose Creek mine, Indian Creek subdistrict, southeast Missouri." 1987. http://hdl.handle.net/2152/20448.
Повний текст джерелаtext
Dobosz, Agatha. "Characterization of Carlin-Type Auriferous Arsenian Pyrite from the Goldstrike Property using EMP, SIMS, and VESPERS Synchrotron u-XRF: Constraints to Ore Deposition Mechanisms." Thesis, 2012. http://hdl.handle.net/1974/7447.
Повний текст джерелаThesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2012-08-27 14:03:12.542
Syu, Jia-Wei, and 許家瑋. "Growing one-dimensional Indium Oxide Nanowires by Chemical Vapor Deposition." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/5a2shq.
Повний текст джерела國立東華大學
材料科學與工程學系
95
In recent years, nanostructures have attracted much attention because of the potential for electronic and optoelectronic applications. Nanostructured semiconductors such as III-V and oxides have been studied and developed. Nanostructured indium oxide ( nanowire, nanobelt, nanoparticles et al.), a wide band-gap ( 3.55 eV – 3.76 eV ) transparent semiconducting material, has been widely used in the microelectronic applications including solar cells, flat panel display materials, and gas sensors. Several one-dimensional In2O3 nanowires and nanorods have been fabricated by using different methods such as laser ablation, electrodeposition and oxidizing method, one-step annealing method, physical vapor deposition, and chemical vapor deposition etc. However, the growth of one-dimensional In2O3 by the CVD method with indium metal or In2O3 powder as the indium sources was carried out at higher temperatures above 800oC. In general, they use indium metal or In2O3 powder as original source. Here we reported a method of growing In2O3 nanowires at lower temperatures of 600 – 700 oC with a novel indium source combining indium shot and InCl3 powder. The process parameters such as the indium source, the temperature of indium source, the growth temperature, the growth duration, the oxygen flow rate, and the substrate were investigated to study the growth of one-dimensional In2O3 nanowires. 1-D In2O3 nanowires with a diameter of 10 – 40 nm and a length of several tens to several hundreds micrometers were obtained with a combined indium source at temperature of 450oC, under growth temperatures of 600 – 700oC, and with a oxygen flow rate of 20 sccm. The produced InCl vapor from the combined indium source was responsible for the growth of 1-D In2O3 nanowires. In-Au alloy catalysts at the tip of In2O3 nanowires were observed by TEM, which identified a growth mechanism of vapor-liquid-solid (VLS). The structure of In2O3 nanowires was cubic with the aid of TEM analysis. The growth of our 1-D In2O3 nanowires involved the steps of the formation of InCl vapor, the coverage of adsorbed InCl and oxygen on Au catalyst, the dissociation of InCl and dissolution of indium into the gold catalyst, and the over-saturation of indium in Au.
Huang, Sung-Chien, and 黃松建. "Growth of one dimensional GaN nanostructure by using chemical vapor deposition." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/vb63vv.
Повний текст джерела國立臺灣科技大學
化學工程系
95
Gallium nitride(GaN) nanostructure were grown by metalorganic chemical vapor deposition using trimethylgallium(TMGa) as source material for Ga, and Ge nanowire、ZnO nanorod、Si(111) with 1 nm of Au as substrates. Si(111) coated with 1 nm Au was acted as a substrate. Heating the substrate until its temperature was 800℃ would form a sheet-like nanostructures. In the other hand, heating the substrates until its temperature was 550℃ would form a rod-like nanostructures. Well-aligned GaN nanorod structure were formed by increasing the feed ratio of Ⅴ/Ⅲ to 15000. GaN nanodots were formed on Ge nanowire substrate. Core-shell structure of GaN/ZnO nanorod、GaN/Ge nanowire were formed by atomic layer epitaxy(ALE) technique. The selective growth process of GaN nanorod on ZnO nanorod, which was coated with SiO2 and acted as substrate, was failed due to high temperature(850℃) and high NH3 concentration.
Ya-HwangCheng and 鄭亞寰. "Fabrication of one dimensional insulated micropattern of silica by electrophoretic deposition." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/26960780855311366373.
Повний текст джерела國立成功大學
材料科學及工程學系碩博士班
98
Micropattern of silica was fabricated on interdigitated array (IDA) electrode, which is an ideal structure of MLCC (multilayer ceramic capacitor) by EPD (electrophoretic deposition). This technique was applied to fabricate insulated layer of inner electrode of MLCC to increase the effective capacity area. First, silica powder was dispersed with different methods in isopropanol (IPA) and then suspension properties were analyzed. From this analysis, it is found that isoelectic point (IEP) of silica was close to 5, zeta potential of silica reached maximum value of -38 mV at pH=10.5, and the average particle size was estimated to be 58 nm. Then, silica particles were deposited on IDA electrodes using ether two electrodes or three electrodes system by EPD. The three electrodes system produced better deposition selectivity, which may due to electric field distribution. Smaller IDA electrode performed faster deposition rate and need lower voltage to fabricate micropattern. Crack-free micropattern of silica was fabricated under applied voltage of 10 V for 20 s followed sintering at 800?C. The resistance of micropattern was found to be 7.04×109 ohm measured by electric property analyzer, and the adhesion of micropattern was better after sintering. Base on results, EPD process using three electrodes system was very fast, with high selective and was suitable for fabrication of insulated layer for MLCC.
Kuo, Chih-Yun, and 郭芷昀. "Atomic layer deposition of Pt catalysts on one dimensional InN nanostructures." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/26636397062512083982.
Повний текст джерела國立臺灣科技大學
化學工程系
96
One-dimensional InN nanostructures with large surface area and high conductivity were used as templates for the deposition Pt catalyst by using atomic layer deposition (ALD) method. The chemical composition, morphology and electrochemical characteristics which were applicable for the anode electrode for direct methanol fuel cell (DMFC) were also investigated. First, the growth mechanism in a ALD system using CpPtMe3 as the precursor was investigated. The growth could be separeted into three regions:(1) Ts < 2500C, a part of precursor was decomposed to form dimethyl platinum which causes steric hindrance on the substrate surface. (2) 2500C < Ts < 3000C:precursor was decomposed to form methyl platinum and matched self-limiting mechanism. (3) Ts > 3500C:precursor was decomposed to form platinum atom and multilayer-adsorption occurred on the surface. Then, a typical ALD Pt deposition condition that applied 5.71×10-4 torr Pt precursor for 3 seconds exposure and [O2] = 28.6% for 2 seconds exposure at 3000C was used for Pt deposition on InN nanostructures. TEM results showed that the deposition of Pt catalyst on InN was polycrystalline and the average diameter of Pt cluster was about 9-11 nm. Decreasing the growth temperature to 2800C showed a better Pt coverage result of slightly (111) oriented on InN nanostructures. A cyclic voltammetry measurement with respect to methanol showed quite a small onset potential at 0.34V, coincident with the value (0.35V) for single crystalline Pt(111).
Lin, Pin-Wei, and 林品緯. "Chemical Bath Deposition of ZnS and Its Application to One-dimensional Sensors." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/28597054796053837690.
Повний текст джерела國立中興大學
材料科學與工程學系所
105
A novel fabrication technique for single crystalline ZnO(002) nanorods has been proposed in this research. First, a chemical-bath deposited (CBD)ZnS thin film was prepared on sapphire substrate. Then, the ZnO was grown by pulsed laser deposition (PLD) on the CBD-ZnS at a substrate temperature of 900 ?C. When the substrate temperature was increased to 900 ?C, the ZnS film can be decomposed to Zn nanoparticles and sulfur fumes. The sulfur fumes were exhausted; meanwhile, Zn nanoparticles were formed on sapphire. The formation of Zn nanoparticles with the hexagonal Zn(002) phase is helpful to grow the single crystalline ZnO(002) nanorods. In comparison to conventional poly-crystalline ZnO nanorods deposited by hydrothermal and vapor–liquid–solid methods, the single crystalline ZnO nanorods presented in this study possess a higher crystal quality. Thus, the metal-semiconductor-metal photodetectors (PDs) fabricated with the single crystalline ZnO nanorods have an excellent optoelectronic performance. The effects of Zn/S ratio and film’s thickness of CBD-ZnS on the ZnO morphology and device performance were also investigated. First, the thickness of ZnS films was fixed at 60 nm, and the Zn/S ratios of 1/50, 1/100, and 1/150 were selected. It can be found that the PLD-ZnO grown the ZnS layer with the Zn/S ratio of 1/100 possessed a more obvious nanostructure. Under a bias voltage of 1 V, the dark currents of the ZnO PDs prepared on the ZnS layers with Zn/S ratios of 1/50, 1/100, and 1/150 were 1.57×10-7, 1.26×10-7, and 2.57×10-8 A, while their photocurrents were measured to be 1.06×10-5, 2.41×10-5, and 8.06×10-7 A, respectively. The signal-to-noise ratios of these three PDs were 67.5, 191.3, and 31.4, respectively. Then, the Zn/S ratio of ZnS film was kept at 1/100, and three thicknesses of 60, 90, and 120 nm were chosen. The dark currents (@1 V) of the ZnO PDs grown on the 60-, 90-, and 120-nm-thick ZnS layers were 1.26 × 10-7, 2.18 × 10-7, and 7.54 × 10-8 A, while their photocurrents (@1 V) were 2.41 × 10-5, 6.25 × 10-5, and 3.75 × 10-6 A, respectively. The signal-to-noise ratios of these three PDs were 191.3, 286.7, and 49.7, respectively. Based on the results, when the Zn/S ratio and thickness of the ZnS film were 1/100 and 90 nm, respectively, the ZnO PD fabricated on the CBD-ZnS possessed the optimum optoelectronic performance.
"Growth of one dimensional Zinc selenide nanostructures by metalorganic chemical vapor deposition." 2004. http://library.cuhk.edu.hk/record=b5892039.
Повний текст джерелаThesis (M.Phil.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (leaves 80-82).
Text in English; abstracts in English and Chinese.
Leung Yee Pan = li yong you ji jin shu hua xue qi xiang chen ji fang fa sheng chang yi wei xi hua xin na mi jie gou / Liang Yibin.
Acknowledgements --- p.ii
Abstract --- p.iii
Chapter Chapter 1 - --- Introduction --- p.1
Chapter 1.1 --- Background --- p.1
Chapter 1.2 --- Motivation --- p.3
Chapter 1.2.1 --- ZnSe --- p.3
Chapter 1.2.2 --- MOCVD --- p.3
Chapter 1.3 --- Our Work --- p.4
Chapter Chapter 2 - --- Experiment --- p.5
Chapter 2.1 --- MOCVD System --- p.5
Chapter 2.2 --- Metalorganic Sources --- p.5
Chapter 2.3 --- Substrates --- p.7
Chapter 2.4 --- Substrate Preparations --- p.7
Chapter 2.5 --- Preheating (Applied Only when Using GaAs Substrates) --- p.7
Chapter 2.6 --- Growth of Epi-layer (Applied Only when Using GaAs Substrates) --- p.8
Chapter 2.7 --- Growth of ZnSe Nanowires on Si(100) and ZnSe/GaAs(100) --- p.8
Chapter 2.8 --- The Samples --- p.9
Chapter Chapter 3 - --- Characterization --- p.10
Chapter 3.1 --- Surface Morphologies --- p.10
Chapter 3.1.1 --- Scanning Electron Microscopy --- p.10
Chapter 3.1.2 --- Atomic Force Microscopy --- p.12
Chapter 3.2 --- Structural Properties - X-Ray Diffraction --- p.13
Chapter 3.3 --- Optical Properties - Photoluminescence --- p.15
Chapter 3.4 --- Other Techniques --- p.16
Chapter Chapter 4 - --- Results --- p.17
Chapter 4.1 --- ZnSe Nanowires Grown on Si(100) --- p.17
Chapter 4.1.1 --- Effect of Growth Temperature --- p.17
Chapter 4.2 --- Growth of ZnSe Nanowires on GaAs( 100) - The First Trial --- p.20
Chapter 4.3 --- Optimizing the ZnSe Epi-layer --- p.21
Chapter 4.3.1 --- Surface of GaAs(100) --- p.21
Chapter 4.3.2 --- ZnSe Epi-layer Grown at Different Reactor Pressures --- p.22
Chapter 4.4 --- Importance of Au --- p.26
Chapter 4.5 --- Growth of ZnSe Nanowires on GaAs(lOO) - A Systematic Study --- p.28
Chapter 4.5.1 --- Growth Rates --- p.28
Chapter 4.5.2 --- Overall Morphologies --- p.32
Chapter 4.5.3 --- Classifying the Morphologies --- p.37
Chapter 4.5.4 --- Abundances of Different Morphologies of Different Samples --- p.40
Chapter 4.5.5 --- Growth Direction --- p.45
Chapter 4.5.6 --- Structure of the Nanowires --- p.50
Chapter 4.5.7 --- Optical Properties of the Nanowires --- p.54
Chapter Chapter 5 - --- Discussions --- p.57
Chapter 5.1 --- Overview of the MOCVD Process --- p.57
Chapter 5.1.1 --- Effects of Growth Temperature on Growth Rate of MOCVD --- p.58
Chapter 5.1.2 --- Effects of Reactor Pressure on Growth Rate of MOCVD --- p.59
Chapter 5.2 --- Effect of Reactor Pressure on the Growth Rate of the Nanowires --- p.60
Chapter 5.3 --- Growth Mechanisms of the Nanowires --- p.64
Chapter 5.3.1 --- VLS Mechanism --- p.64
Chapter 5.3.2 --- Spiral Growth Mechanism --- p.66
Chapter 5.3.3 --- Reentrant Corner Mechanism --- p.67
Chapter 5.3.4 --- Roles of Au Particles and ZnSe Epi-layer --- p.68
Chapter 5.3.5 --- Growth Mechanisms of Different Types of Nanowires --- p.69
Chapter 5.3.6 --- Effect of Growth Temperature --- p.71
Chapter 5.4 --- Quality of the Nanowires --- p.72
Chapter 5.5 --- "Remarks of the AFM Experiments and the ""Transferred"" Samples" --- p.72
Chapter Chapter 6 - --- Conclusions --- p.75
Appendices --- p.77
Chapter I - --- "Estimation of the mass, other than the nanowires, contributed to the sample" --- p.77
Chapter II - --- Calculation of the growth angle with respect to the surface normal --- p.78
References --- p.80
Shih, Yao-Yin, and 施堯尹. "Preparation of directional one-dimensional ZnO nanorods by atmospheric chemical vapor deposition." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/23duh5.
Повний текст джерела國立東華大學
材料科學與工程學系
96
In this research, we prepared well-aligned ZnO rods which were grown vertically on substrate, by atmospheric chemical vapor deposition method. We discussed the dependence of growth of ZnO rods on two different parameters. We changed the Ⅵ/Ⅱ ratios and the growth temperature in order to study the dependence of morphology and preferred orientation. The result of our experiment shows that high Ⅵ/Ⅱ ratios promote the growth of ZnO rods whereas low Ⅵ/Ⅱ ratios do not promote the growth of ZnO rods. Neither too high nor too low of growth temperatue will not promote the growth of ZnO rods. Finally, With growth rate of 9.11nm/min, substrate temperature of 575℃, and Ⅵ/Ⅱ ratios larger than 5848, we could obtain well-aligned ZnO rods which were grown vertically on substrate.
Ting, sheng-hung, and 丁勝紘. "Synthesis and Characterization of One-Dimensional SnO2 Structure by Chemical Vapor Deposition." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/73875678094421622274.
Повний текст джерела逢甲大學
電子工程所
97
In this study, one-dimensional SnO2 nanostructure has been synthesized on ITO/glass substrate via chemical vapor deposition in low temperature with vapor-liquid-solid (VLS) mechanism. Morphology of SnO2 nanowire arrays were observed with field emission scanning electron microscopy (FE-SEM). The crystal structures of the nanowires were identified by X-ray diffraction (XRD) utilizing Cu Kα radiation. Chemical composition of the as-prepared SnO2 nanowire arrays were analyzed by energy dispersive spectrometer (EDS).
Yang, Jen Hung, and 楊仁泓. "Localized Electrochemical Deposition Process and Mechanical Property Measurements for One-Dimensional Structure." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/29732561313097892033.
Повний текст джерела大葉大學
機械工程研究所碩士班
92
In general, electrochemical deposition has been employed to deposit metal on the metallic surface (plating) or to deposit metal for duplicating the patterns prepared by photolithographic process (electroforming). However, if by locally controlling the induced electric field to deposit metal, the lithography process for prepare the pattern by marks can be spared. Thus, it can reduce fabrication cost and error of masks or molds. Furthermore, using a localized electrochemical deposition can deposit micro-sized structures with high aspect ratio easily. Usually, the structure which is fabricated by micro-process, demonstrates mechanical properties different from its bulk materials counterpart. In this study, we use a localized electrochemical deposition to fabricate a cantilever beam of Cu which is in the dimensions of micrometers. The effects of various control parameters of the deposition process are also studied. The first resonance frequency of the deposited structure is measured by the forced vibration at its base. The Young’s modulus of the micro-structure is then inferred from the resonance frequency and several possible factors which affect the apparent stiffness are discussed. Because a stepping mode is used to deposit micro-structure in the experiment, a nodular micro-structure has been obtained. Therefore, this study also design a magnification mechanism which is composed of linkages connected by flexure hinges and is driven by a piezoelectric actuator. The continuous movement instead of stepped movement of the electrode with feedback control, should overcome the shortcoming of the previous study.
Yu, Chi-Chung, and 尤啟中. "Growth of One-Dimensional SiOx and TiO2 Nanostructures Using Chemical Vapor Deposition." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/44011566065347659092.
Повний текст джерела國立成功大學
化學工程學系碩博士班
91
The growth characteristics of one dimensional nc-Si/SiOx composite nanowires using SiCl4/H2 as well as oxygen absorbed on chamber wall in a hot-filament chemical vapor deposition reactor were investigated in this study. The composite nanowires were grown on various substrates by non-VLS mechanism at lower substrate temperatures in comparison with polycrystalline film formed at high temperature. Structural and compositional characterizations of the nanowires by TEM and electron energy-loss spectroscopy (EELS) indicate that dendritic self-assembly of Si nanorods are embedded in the amorphous SiOx nanowires. PL analyses of the nc-Si/SiOx composite nanowires show a blue-green light emission at room temperature. Aligned rutlie and anatase TiO2 nanorods as well as anatase TiO2 nanowalls have been synthesized using a template- and catalyst-free CVD method. Formation of various crystal phases and morphologies of TiO2 nanostructures were dependent on the substrate temperatures as well as the distances between the Ti source and the substrates. Anatase films, nanowalls and well-aligned nanorods were formed at substrate temperatures of 420~485℃, 500~535℃ and 560~605℃, respectively. Rutile nanorods were grown at substrate temperatures of 630~655℃ in a longer distance between Ti source and substrate. TEM analyses indicate that rutile and anatase TiO2 nanorods were both single crystalline. Optical characterizations of the TiO2 nanostructures show that the bandgap of anatase and rutile phase were 3.2 as well as 3.0 eV, respectively.
"Origin of high-grade hematite ores at Thabazimbi Mine, Limpopo Province, South Africa." Thesis, 2009. http://hdl.handle.net/10210/1965.
Повний текст джерелаHigh-grade hematite ores at the Thabazimbi Mine, Limpopo Province, occur as stratabound bodies in the Early Paleoproterozoic Penge Iron Formation of the Transvaal Supergroup. Iron ores occur at three distinct positions in the Penge Iron Formation (i) basal ore bodies located immediately above a thin oxidised shale unit that marks the base of the Penge Iron Formation in the Thabazimbi area and that may be interpreted as a structural contact towards the underlying dolostones of the Malmani Subgroup; (ii) ore bodies developed immediately above a prominent mafic sill in the Penge Iron Formation; (iii) small, lenticular ore bodies developed in the iron-formation without apparent structural control. Ore bodies in all three stratigraphic positions formed on the expense of the Penge Iron Formation protore, they share very similar mineralogical and textural attributes and can be subdivided into three major ore types with respect to their mineralogy and physical characteristics, namely, (a) carbonate-hematite ore; (b) hard hematite ore; (c) supergene modified ore. Further subdivision into subtypes is possible based on textural attributes. The first stage of iron ore formation at the Thabazimbi deposit is marked by oxidation of ferrous minerals (carbonates and grunerite) and their replacement by hematite. Efficient leaching and replacement of chert in the iron-formation to produce high-grade hematite ores characterizes the second stage of alteration. Stable isotope and fluid inclusion evidence point to a hydrothermal origin of the iron ores. Two hydrothermal fluids were identified, namely a highly saline Ca-Mg-rich brine (S = 27 wt% NaClequiv, TH = 160ºC) and a Nadominated fluid of intermediate salinity (S = 10 wt% NaClequiv, TH = 130ºC) that is possibly of meteoric origin. The results obtained in this study are used to propose the following sequence of mineralising events for the Thabazimbi iron ore deposit: (i) Deposition of iron-formation and diagenesis; (ii) contact metamorphic alteration related to the intrusion of the Bushveld igneous complex; (iii) metasomatic oxidation, leaching and residual upgrading that is tentatively linked to structurallycontrolled hydrothermal fluid flow; (iv) supergene modification of existing high-grade ore bodies in post-Gondwana times along the old African land surface.
Yang, Chu-Hao, and 楊筑皓. "Dielectric Barrier Discharge Based Remote Atmospheric Pressure Plasma Deposition for One-step Protein Immobilization." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/qh5xgu.
Повний текст джерела國立交通大學
機械工程系所
107
In recent years, atmospheric pressure plasma (APP) has been widely used for bio-medical applications. APP can achieve non-thermal and mild discharge, reducing the heat influence to bio molecules. Without using vacuum systems, the cost of APP system can become lower. In this study, a dielectric-barrier-discharge based remote APP deposition (DBD RAPPD) system is used for protein immobilization. Since in APP system the deposition is occurred in the discharge region, protein may be denatured or damaged by the factors in the plasma, like heat, reactive species and UV. The deposition region is limited by area of the electrode in APP system. With remote plasma, deposition can occur at the downstream region of the plasma. Influence of plasma on protein can be reduce, large surface treatment and uniform coating can be achieve by this DBD RAPP system. The DBD RAPP system used two parallel plate DBD, which has a 1mm distance between them. Aluminum tapes (50mm x 50 mm) are used as the electrodes. The working gas in plasma is helium, and the precursor is ethylene. The protein we used is BSA (Bovine serum albumin). Helium goes through the atomizer to generate protein aerosol. Ethylene reacts with plasma and becomes plasma-polymerized ethylene (ppE) then deposited onto the substrate. Upstream mixing (mixing BSA aerosol and ethylene before gas going through the discharge region) and downstream mixing (mixing BSA aerosol and ppE at the downstream region outside the discharge) are used for experiments discussions. BSA is immobilized by entrapment of ppE or bonded with functional groups. FTIR was used for analyze the composite of coatings. SEM was used for investigate the morphology of coating surfaces. The coatings were rinsed by micro fluid to detect BSA adhesion. Surface profiler was used to analyze the thickness of coatings. Immunostaining was used for detecting the protein activity. In the result the signal and structure of BSA-ppE coating are detected and remained after rinse. Some appropriate experiment parameters for the immobilization are found.
Hicks, Nigel. "A combined sedimentological-mineralogical study of sediment-hosted gold and uranium mineralization at Denny Dalton, Pongola Supergroup, South Africa." Thesis, 2009. http://hdl.handle.net/10413/1194.
Повний текст джерелаThesis (M.Sc.)-University of KwaZulu-Natal, 2009.
Lo, Yu-Chun, and 羅于珺. "Preparation and Applications of One-Dimensional Fluorine-doped Tin Oxide Nanostructure with Vapor-deposition Processes." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/90772350709171450726.
Повний текст джерела國立清華大學
化學工程學系
102
One-dimensional nanostructure is much easily and quickly for electron transfer, therefore many kinds of one dimensional structural materials were developed and used in various fields. Semiconducting SnO2 is a key functional material that has been used extensively for optoelectronic devices and sensors. Because the conductivity of SnO2 is not notable, SnO2 often doped with different atoms in order to improve and enhance the carrier concentration and electrical properties. FTO, fluorine-doped tin oxide, because of its excellent visible light transparency and electric conductivity, has found extensive applications in optoelectronics, display, and photovoltaic devices as a transparent conductive electrode. In this study, we aim to alter the 2-D flat FTO film to fabricate an extended 3-D FTO structure, to increas its surface areas and roughnesses, and effectively shorten the path of electron transfer. In the first part of this study, we developed a vapor-solid (VS) process, to successfully grow 1-D nanocone FTO on commercial FTO substrates for applications in dye-sensitized solar cells (DSSC) as the anode substrate. Through the investigation of the effect of the NH4F/SnCl2‧2H2O ratio in the anode substrate fabrication, we found that the power conversion efficiency (PCE) of the DSSC changed accordingly. When the doping ratio was 0.5, the PCE was slightly enhanced to 6.19 %. As compared with the PEC obtained by using commercial FTO as the anode substrate (5.52 %), the PCE has increased 12%. The good contact between the TiO¬2 and the present 1-D FTO anode substrate led to smaller contact resistances (Rco). This further resulted in a large fill factor of 0.74 and small R1 of 3.72 Ω. In the second part, we developed a vapor-liquid-solid (VLS) process, employing gold nanoparticles as the catalyst, to grow FTO nanowires on commercial FTO substrate. These 1-D FTO structure samples were prepared inside a quartz tube, with flowing N2 and air to adjust oxygen concentration for SnO2 nanowire formation and NH4F as the fluorine source for in-situ F-doping. The products showed low sheet resistances and high hydrophilicity, and thus possessed a great potential for applications in H2O2 sensing through Pt-loading. Because of the poor hydrophilicity of the commercial FTO, the amount of Pt loading was limited, which affected its sensing performance. The nanowire length of sample Au-FTO NWs-3hr was about 750 nm, and was good for Pt loading. This sample showed a high sensitivity of 272 mA/M. This study successfully develops a promising and novel sensing electrode, which is conducting, of high surface area, and highly hydrophilic.
Chen, Reui-San, and 陳瑞山. "Growth Control of Iridium Dioxide One-Dimensional Nanocrystals and Thin Films Using Metal-Organic Chemical Vapor Deposition." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/38448336272257955910.
Повний текст джерела國立臺灣科技大學
電子工程系
93
Via the technique of vertical-flow cold-wall metal-organic chemical vapor deposition (MOCVD) using highly volatile (MeCp)(COD)Ir as the CVD precursor, conductive iridium dioxide (IrO2) one-dimensional (1D) nanocrystals, including nanorods (NRs) and nanotubes (NTs), as well as thin films have been successfully deposited on various substrates. A detailed characterization focusing on the morphology, structures, orientations, and compositions of the various IrO2 samples have been carried out by means of field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected-area electron diffractometry (SAED), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and Raman scattering. The field emission characteristics of the IrO2 NRs with pointed tips are also studied. The effects of chamber pressure (Pc) and substrate temperature (Ts) on the growth phase transformation from Ir metal, mixed Ir/IrO2 to IrO2 have been observed. The dioxide phase of iridium is found to be preferentially formed under the combined CVD conditions of higher oxygen ambient pressures (Pc = 10 - 50 Torr) and higher temperatures (Ts ³ 350 °C); otherwise iridium metal phase is obtained at either lower pressure (Pc = 1 Torr) or lower temperatures (Ts £ 300 °C). It is worth noting here that IrO2 undergoes a gradual change of crystallization behavior from isotropic 3D particulates to 1D rod-like crystals while lowering the deposition temperatures from 450 to 300 °C at 30 Torr of pressure. IrO2 1D nanocrystals are always obtained at a temperature of 350 °C under a relatively high pressure of 30 Torr. Electrical measurements show the polycrystalline IrO2 films have room temperature resistivity of 80 ± 8 mW-cm. The alignment and density of the IrO2 1D crystals have been improved using titanium (Ti) and indium (In) coated silicon(100) substrates as compared to the direct growth on the bare silicon(100) substrate. The IrO2 1D crystals with vertical alignment and nearly unique (001) out-planed orientation have been reached by depositions on sapphire (SA)(100) and LiNbO3 (LNO)(100) substrates. The analysis of lattice relationship between IrO2(001) plane and (100) plane of sapphire and LiNbO3 shows the in-planed orientation relationship: IrO2[100] // SA[010] and IrO2[100] // LNO[010]. An interesting tilted growth of well aligned IrO2 1D materials has been observed using LiTaO3 (LTO)(012) substrate. The SAED and XRD measurements indicate the epitaxial growth of IrO2 on LTO (012) with the orientation relationship given by IrO2(101)//LTO(012) and IrO2 //LTO[100]. The initial IrO2(101) epitaxial nucleation on the LTO(012) surface was found to be the key factor leading to the growth with a tilt angle ~35°. The tilted growth has been further observed in the IrO2 growth on the other oxide substrates including SA(012), SA(110), LTO(110), yttrium-stabilized ZrO2 (YSZ)(100) and YSZ(111). Among the results of tilted growth, IrO2 1D crystals grown on LTO(012) and SA(012) substrates exhibit singly aligned direction; meanwhile IrO2 on LTO(110) and SA(110) exhibit symmetrically doubly aligned directions. Growth patterns with quadruply and sextuply aligned-directions are observed on the YSZ(100) and (111) substrates, respectively, which is attributed to the lattice relationship between rectangular IrO2(101) plane and square (100) and hexagonal (111) planes of YSZ. From a morphological study, the controlled growth of IrO2 1D nanocrystals, including various NRs and NTs, has been done. The evolution from triangular/wedged NRs, via incomplete/scrolled NTs to hollow square NTs and solid square NRs has been observed as we decrease the growth rates of the 1D materials. Our results show the single-wall NT is more energetically favorable than other tubular forms and the solid square NR is the most stable form for the tetragonal rutile material of IrO2. A spiral mode and the growth rate-dependent kinetics were supposed to be the main mechanism resulting in the morphological evolution. The structural characterization by TEM, SAED and XRD shows the single-crystalline quality and an identical preferred c-axis growth direction for the IrO2 NRs and NTs. The XPS examinations show common stoichiometric characteristics, including the excess oxygen content and a higher oxidation state, for the IrO2 1D material. The micro-Raman spectra show red-shift and peak broadening of the IrO2 signatures with respect to that of the bulk counterpart which may be indicative of a phonon confinement effect for these NTs. The unique geometrical features of IrO2 NRs, including nanosized structure and self-assembled sharp tip, exhibit a strong effect on field enhancement (b ~ 40000), which result in a low threshold field (Eth ~ 0.7 V/mm) defined at the beginning of emission. A low turn-on field for driving a current of 10 mA/cm2 is about 5.6 V/mm, which is comparable with the carbon nanotube, diamond, and amorphous carbon. The potential of using IrO2 nanorods as an emitter material has been demonstrated.
Chen, Chih-jung, and 陳志榮. "Synthesis and Characterization of One-Dimensional Indium Zinc Oxide and Tin Oxide Structure by Chemical Vapor Deposition." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/86152193625492345715.
Повний текст джерела逢甲大學
電機與通訊工程所
98
In this study, one-dimensional Indium Zinc Oxide (IZO) and tin oxide (SnO2) nanostructures have been successfully synthesis on ITO glass substrate via chemical vapor deposition in low temperature with vapor-liquid-solid (VLS) mechanism. Morphology of IZO and SnO2 nanowires arrays were observed with field emission scanning electron microscopy (FE-SEM). The IZO nanowires optimal experimental parameters are growth pressure is 1 Torr, argon gas flow of 50 sccm and oxygen flow 10 sccm. In this environment, the idea temperatures are 700 ℃ for indium (In) particles and 550 ℃ for zinc (Zn) particles. Nanowires have uniform diameters of approximately 100 nm to 150 nm, and their lengths are up to tens of 5 μm The SnO2 best growth temperatures are 450 ℃ and growth pressures were 8 × 10-1 Torr, respectively. In the catalyst, the nickel (Ni) catalyst compared to platinum (Pt) catalyst is a more effective reduction of one-dimensional SnO2 nanostructure on the ITO glass, the length of nanowires is about 1 μm ~ 2 μm, under the catalytic reaction conditions and low-temperature growth processes of one-dimensional SnO2 nanostructure on the ITO glass with an average diameter of about 20 nm ~ 50 nm. The X-ray diffraction (XRD) results show that the as-synthesized nanowires are crystalline with highly preferential orientation. Energy dispersive spectrometer (EDS) analysis shows that the composition ratio and confirmed in this material are indeed IZO and SnO2 nanowires.
Chen, Shih-Wei, and 陳世偉. "Morphology Evolution of Co Thin Films during Deposition by DC Magnetron Sputtering and Their Applications for OME Process." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/34874910606785424657.
Повний текст джерела國立成功大學
材料科學及工程學系碩博士班
91
The cobalt thin films are grown by D.C. magnetron sputtering as a function of the target-to-substrate distance, bias and power on both Si (100) and (111) substrates. The crystal structure and morphology of the thin films are characterized by x-ray diffraction, scanning electron microscopy, transmission electron microscopy and atomic force microscopy. It is found that the cobalt crystal structure can be varied from HCP to FCC by varying the target—to-substrate distance from 6 to 10 cm. The roughness and the preferred orientation of the thin films are greatly affected by the substrate bias and power. In addition, pyramid-like nanostructures with sharp tips are formed on the surface of the thin films when negative bias is applied. The faceted planes on the nanostructures depend on the resulting Co crystal structure while the size and density are determined by the growth parameters. The evolution of the surface nanostructures are systematically examined as a function of substrate bias and thin film thickness. The formation mechanism of the surface nanostructures is discussed in the paper. We use D.C. magnetron sputtering to form CoSi2 by OME (Oxide-Mediated Epitaxy) Process. Thickness of Co films is sensitive for OME process, we can get uniform Co film about 3~6 nm by sputtering. Growth difference of CoSi2 can be varied by using different parameter, like annealing by two steps that are 460℃ for 60 seconds and 600℃ for 60seconds, substrate be implanted more silicon, and design the sandwich structure of OME process.CoSi2 thin film can grow uniform by sandwich structure and annealing by two steps.