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1
Atta-Fynn, Raymond. "Theory of localized electron states and novel structural modeling of amorphous silicon /." View abstract, 2005. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3203330.
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Punsalan, David Troy. "A sorption and dilation investigation of amorphous glassy polymers and physical aging." Access restricted to users with UT Austin EID, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3035168.
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Saito, Ichitaro. "Amorphous selenium photoelectric devices." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610017.
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Jiang, Yucheng, and 姜昱丞. "Magnetoresistance, photoconductivity and strain effect in the system of magnetically doped amorphous carbon." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208021.
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Gabriel, Margaret A. "Electronic defects in amorphous silicon dioxide /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8553.
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Goldstein, Alexandra Susan. "Computer simulations of amorphous copper-zirconium /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/8629.
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Chieng, Heng Liang Norman, and n/a. "Amorphous drug preparation using ball milling." University of Otago. School of Pharmacy, 2008. http://adt.otago.ac.nz./public/adt-NZDU20081209.162001.
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Polymorphism and crystallinity are now recognised as important issues in drug development. This is shown by the increased amount of research in this area over recent years. In pharmaceutical development milling is an important unit operation for size reduction to improve powder handling, processing and dissolution rate. The aim of this thesis was to investigate the effect of ball milling (and cryo-milling) on the solid state properties, including amorphous drug formation, of pharmaceutical solids.
Milling was carried out using an oscillatory ball mill (Mixer Mill MM301, Retsch GmbH & Co., Germany). In cryo-milling the milling jars were immersed in liquid nitrogen for three min before milling. XRPD was used as the main technique to evaluate the milled samples. Ranitidine hydrochloride (RAN) and indomethacin (INDO) were the model drugs used in this study.
It was found that upon milling, RAN form 1 converts to RAN form 2 via an amorphous phase. A faster amorphization rate was observed when the crystalline samples were cryo-milled. Amorphous ranitidine hydrochloride was characterized to have a glass transition (T[g]) range of 13 to 30 �C and a crystallization exotherm (T[c]) between 30 and 65 �C. Conversion was found to occur faster when the temperature of the solid powder was greater than the T[c]. Under various storage conditions, similarly, crystallization of the amorphous phase mainly led to RAN form 2. However, some form 1 and amorphous phase was also detected on the XRPD diffractograms. Using partial least squares regression, the amount of solid form components in the ternary RAN mixtures were successfully quantified. RAN form 2 did not convert to form 1 under any milling (including cryo-milling) or storage conditions used in this study. Overall, RAN form 2 was found to be the thermodynamically stable form and the two (RAN) polymorphs are likely to be a monotropic pair.
In a co-milling study of INDO and RAN, the two crystalline drugs were successfully converted into a single amorphous phase after 60 min of co-milling in a cold room (4 �C). The T[g] range (26-44 �C) was also characterized for these mixtures. DRIFTS spectra of the co-milled amorphous samples indicated an interaction had occurred between the carboxylic acid carbonyl (HO-C=O) and benzonyl amide (NC=O) of the INDO molecule with the aci-nitro (C=NO₂) of RAN. Depending on the ratio of INDO to RAN, in general, the amorphous mixtures were stable at 4 �C after 30 days of storage. Crystallization was faster when the binary mixtures were stored at higher temperature or contained higher amounts of RAN in the mixture. Although XRPD and DRIFTS suggested an interaction between the two drugs, co-crystal formation was not observed between INDO and RAN.
Ball milling can be used to produce amorphous drug. The rate and extent of amorphization is dependent on the milling conditions. A faster rate of amorphization was observed when the crystalline drugs were cryo-milled. Amorphous drug formation can be made either alone or in combination with another crystalline drug. Amorphization could offer a significant improvement on the dissolution profile and the bioavailability of the poorly water soluble drug - indomethacin. Furthermore, ball milling can also be used to produce a homogenous mix between solids. The �goodmix� effect can be used for seed-induced crystallization or, when the XRPD or Raman data were combined with partial least squares regression, to create a reliable calibration model for quantitative analysis.
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Chen, En-Tsung. "On the pressure formation of metallic glasses." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/17978.
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Brüning, Ralf. "Reversible structural relaxation in iron based metallic glasses." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65539.
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Lau, King Cheung. "Crystallization of amorphous alloy and the associated changes of properties." access abstract and table of contents access full-text, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?msc-ap-b21174453a.pdf.
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Thesis (M.Sc.)--City University of Hong Kong, 2005.<br>At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Sept. 1, 2006) Includes bibliographical references.
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Heinz, Andrea, and n/a. "Novel approaches for physicochemical characterisation and quantification of amorphous pharmaceutical compounds." University of Otago. School of Pharmacy, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080924.133134.
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The amorphous state is becoming increasingly important in the pharmaceutical setting. Formulation of poorly water soluble drugs in the amorphous form enhances physicochemical properties of the drug, such as solubility and dissolution rate, which in turn may lead to an increased bioavailability. However, despite these advantages, many properties of the amorphous state are not yet understood and amorphous materials pose a challenge for structural analysis since they lack three dimensional long range order. Hence, compared to crystalline materials often little structural information can be gained using standard characterisation techniques.
In this thesis, a range of analytical techniques and data analysis tools were used to characterise as well as quantify amorphous drugs and compare them to their crystalline counterparts. Apart from established characterisation techniques such as X-ray powder diffraction, microscopy, and differential scanning calorimetry, molecular-level characterisation was carried out using vibrational spectroscopies including infrared, near infrared, and Raman spectroscopy combined with multivariate analysis methods. To obtain deeper understanding of the structure of amorphous drugs and their corresponding crystalline forms novel approaches such as pair distribution function analysis of X-ray diffraction data and computational chemistry were employed.
Three model drugs namely indomethacin, saquinavir, and fenofibrate were investigated in the scope of this thesis. For indomethacin differences between amorphous forms of indomethacin prepared by ball milling, spray drying, as well as melting and subsequent cooling were analysed using infrared, near infrared, and Raman spectroscopy in combination with principal component analysis. While all spectroscopic techniques were able to differentiate between the differently prepared samples, Raman spectroscopy proved to be most sensitive to small differences in the solid state of different samples. Consistent with the study of indomethacin, Raman spectroscopy combined with principal component analysis was the most sensitive analytical technique to detect structural changes induced by milling or heating saquinavir. In addition, pair distribution function transforms of the X-ray powder diffraction data significantly contributed to the understanding of differences in short-range and long-range order between differently treated saquinavir samples.
A combination of vibrational spectroscopy, quantum mechanical calculations, and multivariate analysis proved suitable for physicochemical analysis of amorphous fenofibrate. The results of the study support the idea that non hydrogen bonded molecules such as fenofibrate are likely to exhibit random molecular orientations and conformations in the amorphous phase since the weak intermolecular interactions that occur between such molecules can easily be disrupted.
A study of ternary mixtures of crystalline and amorphous forms of indomethacin showed that Raman and near-infrared spectroscopy in conjunction with PLS regression are well suited for quantification of the different solid-state forms simultaneously. It was found that near-infrared spectroscopy can be used to more accurately quantify the mixtures compared to Raman spectroscopy when fluorescing components, such as amorphous indomethacin, are present. Nevertheless quantification with Raman spectroscopy was still possible.
Overall, the analytical methods used in this thesis were successfully employed for qualitative and quantitative analysis of amorphous drugs and their crystalline counterparts. It could be shown that it is beneficial to use a combination of different analytical techniques and data analysis tools since results are complementary and allow a more comprehensive description of the solid state.
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Lu, Meijun. "Silicon heterojunction solar cell and crystallization of amorphous silicon." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 295 p, 2009. http://proquest.umi.com/pqdweb?did=1654494651&sid=3&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Tse, Shing Chi. "Charge transport and injection in amorphous organic electronic materials." HKBU Institutional Repository, 2007. http://repository.hkbu.edu.hk/etd_ra/821.
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Ковтуненко, В. С. "Застосування квадратичного розподілу міжатомних відстаней координаційних сфер аморфних плівок". Thesis, Видавництво СумДУ, 2012. http://essuir.sumdu.edu.ua/handle/123456789/27632.
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У роботі аналізуються результати проведених математичних
розрахунків параметрів функції розподілу міжатомних відстаней
різних координаційних сфер аморфного кремнію. Показано, що для
різних моделей розподілів міжатомних відстаней координаційних
сфер проявляються суттєві відмінності в загальній сумарній функції
радіального розподілу атомів.
При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/27632
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Katakam, Shravana K. "Laser Surface Treatment of Amorphous Metals." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc500194/.
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Amorphous materials are used as soft magnetic materials and also as surface coatings to improve the surface properties. Furthermore, the nanocrystalline materials derived from their amorphous precursors show superior soft magnetic properties than amorphous counter parts for transformer core applications. In the present work, laser based processing of amorphous materials will be presented. Conventionally, the nanocrystalline materials are synthesized by furnace heat treatment of amorphous precursors. Fe-based amorphous/nanocrystalline materials due to their low cost and superior magnetic properties are the most widely used soft magnetic materials. However, achieving nanocrystalline microstructure in Fe-Si-B ternary system becomes very difficult owing its rapid growth rate at higher temperatures and sluggish diffusion at low temperature annealing. Hence, nanocrystallization in this system is achieved by using alloying additions (Cu and Nb) in the ternary Fe-Si-B system. Thus, increasing the cost and also resulting in reduction of saturation magnetization. laser processing technique is used to achieve extremely fine nanocrystalline microstructure in Fe-Si-B amorphous precursor. Microstructure-magnetic Property-laser processing co-relationship has been established for Fe-Si-B ternary system using analytical techniques. Laser processing improved the magnetic properties with significant increase in saturation magnetization and near zero coercivity values. Amorphous materials exhibit excellent corrosion resistance by virtue of their atomic structure. Fe-based amorphous materials are economical and due to their ease of processing are of potential interest to synthesize as coatings materials for wear and corrosion resistance applications. Fe-Cr-Mo-Y-C-B amorphous system was used to develop thick coatings on 4130 Steel substrate and the corrosion resistance of the amorphous coatings was improved. It is also shown that the mode of corrosion depends on the laser processing conditions. The microstructure evolution and the corrosion mechanisms operating are evaluated using post processing and post corrosion analysis.
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Wilks, Broderick. "Free volume and free volume distribution impact on transport properties in amorphous glassy polymers." Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/9377.
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Kanakala, Raghunath. "Spark plasma sintering of a structurally amorphous metal (SAM7) with addition of Y₂O₃ with nanoparticles." abstract and full text PDF (UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1456485.
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Socratous, Josephine. "Investigating defect states and charge transport in amorphous metal oxides for thin-film transistor applications." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709317.
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Fong, Hon Hang. "Transport and luminance of organic electronic materials." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/612.
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Donev, Jason Matthew Kaiser. "Non-contact atomic force microscopy studies of amorphous solid water deposited on Au(111) /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/9779.
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Li, Huaming. "Theory of phase transitions in disordered crystal solids." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29707.
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Thesis (Ph.D)--Physics, Georgia Institute of Technology, 2009.<br>Committee Chair: Li Mo; Committee Member: Chou Meiyin; Committee Member: First Phillip; Committee Member: Nguyen Toan; Committee Member: Zangwill Andrew. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Gao, Chao. "Spectral momentum densities of crystalline graphite and ion sputtered amorphous carbon films from (e,2e) spectrology." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53693.
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Anooshehpour, Farid. "Optical emission spectroscopy as a process-monitoring tool in PECVD of amorphous carbon coatings." Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/27142.
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Dans ce projet de recherche, le dépôt des couches minces de carbone amorphe (généralement connu sous le nom de DLC pour Diamond-Like Carbon en anglais) par un procédé de dépôt chimique en phase vapeur assisté par plasma (ou PECVD pour Plasma Enhanced Chemical Vapor deposition en anglais) a été étudié en utilisant la Spectroscopie d’Émission Optique (OES) et l’analyse partielle par régression des moindres carrés (PLSR). L’objectif de ce mémoire est d’établir un modèle statistique pour prévoir les propriétés des revêtements DLC selon les paramètres du procédé de déposition ou selon les données acquises par OES. Deux séries d’analyse PLSR ont été réalisées. La première examine la corrélation entre les paramètres du procédé et les caractéristiques du plasma pour obtenir une meilleure compréhension du processus de dépôt. La deuxième série montre le potentiel de la technique d’OES comme outil de surveillance du procédé et de prédiction des propriétés de la couche déposée. Les résultats montrent que la prédiction des propriétés des revêtements DLC qui était possible jusqu’à maintenant en se basant sur les paramètres du procédé (la pression, la puissance, et le mode du plasma), serait envisageable désormais grâce aux informations obtenues par OES du plasma (particulièrement les indices qui sont reliées aux concentrations des espèces dans le plasma). En effet, les données obtenues par OES peuvent être utilisées pour surveiller directement le processus de dépôt plutôt que faire une étude complète de l’effet des paramètres du processus, ceux-ci étant strictement reliés au réacteur plasma et étant variables d’un laboratoire à l’autre. La perspective de l’application d’un modèle PLSR intégrant les données de l’OES est aussi démontrée dans cette recherche afin d’élaborer et surveiller un dépôt avec une structure graduelle.<br>The production of amorphous carbon coatings or as commonly known as diamond like carbon (DLC) coatings, using the plasma enhanced chemical vapor deposition (PECVD) method is studied through optical emission spectroscopy (OES) as a plasma diagnostic technique and the partial least square regression (PLSR) statistical method. The objective is to establish a model to predict DLC properties independent of reactor-related parameters, in order to be used in any other similar deposition process. Therefore the model correlates the deposited coating properties to plasma parameters derived from OES. The OES derived data carries a variety of information about plasma characteristics. The relative spectral line intensities of CH and atomic H to specific Ar lines were employed as a probe of their concentrations according to actinometry method. The full width at half maximum of atomic H was also employed. This method can be used as a probe of gas temperature via Doppler broadening effect. The DLC coatings were characterized using profilometry for thickness and stress measurements and Auger electron spectroscopy (AES) for structural analysis. There were two series of PLSR analysis carried out: The first analysis studies the correlation between process parameters and plasma characteristics, as derived by OES, for a better understanding of the plasma deposition process. The second analysis shows how the OES can be used for prediction of coating properties and for process monitoring. According to the results, the OES data (especially the parameters that are related to the concentration of atomic hydrogen and CH species) are able to represent some parts of process parameters (plasma power, mode and pressure) in a statistical model that is designed for predicting DLC coating properties. In other words, this means that this plasma diagnostic technique can be employed for in-situ monitoring of growing DLC coating properties, instead of using process parameters, which are related to the deposition reactor and may vary from one system to another. The perspective of using the OES data and the PLSR analysis in designing and monitoring a structurally gradient DLC coating is also discussed.
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Van, Order Jon P. "Molecular modeling of intermediate order in polymer glasses." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/10134.
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Kazi, Haseeb. "Plasma Interactions on Organosilicate Glass Dielectric Films and Emerging Amorphous Materials- Approach to Pore Sealing and Chemical Modifications." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc801876/.
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In-situ x-ray photoemission (XPS) and ex-situ FTIR studies of nanoporous organosilicate glass (OSG) films point to the separate roles of radicals vs. VUV photons in the carbon abstraction. The studies indicate that reaction with O2 in presence of VUV photons (~123 nm) result in significant carbon abstraction within the bulk and that the kinetics of this process is diffusion-limited. In contrast, OSG exposed to atomic O (no VUV) results in Si-C bond scission and Si-O bond formation, but this process is self-limiting after formation of ~1 nm thick SiO2 surface layer that inhibits further diffusion. Therefore, the diffusion-dominated kinetics of carbon abstraction observed for OSG exposed to O2 plasma is definitively attributed to the diffusion of O2 down OSG nanopores, reacting at photo-activated sites, rather than to the diffusion of atomic O. Pretreatment of OSG by 900 eV Ar+ ion bombardment also results in formation of 1 nm thick SiO2-like surface overlayer that inhibits O2 diffusion, inhibiting VUV+O2 and O2 plasma-induced reactions, and that the effectiveness of this treatment increases with ion kinetic energy. On the contrary, organosilicate glass (OSG) films with backbone carbon (-Si-R-Si-) exhibit significantly enhanced resistance to carbon loss upon exposure to O2 plasma, radicals and VUV+O2 compared to films with terminal methyl groups (Si-CH3). Films incorporating backbone carbon chains (-Si-R-Si-) were deposited from 1,2 bis (triethoxysilyl) ethane (BTESE) precursor by ebeam or plasma cross-linking. The radical effects on BTESE film indicates negligible carbon loss or Si oxidation, combined with C-O bond formation, under conditions where OSG films with terminal methyl groups exhibit > 80% carbon loss within the surface region of the film. C-O bond formation is never observed for terminal CH3 groups. Further, backbone carbon (-Si-R-Si-) films exposed to VUV+O2 exhibit self-limiting, minimal net carbon loss. This indicates that plasma-induced Si-C bond rupture still occurs in the linking unit, but with a low probability of simultaneous rupture of both Si-C bonds required for abstraction of an in-line methylene bridging group. The data thus demonstrate that OSG films containing backbone carbon groups exhibit greatly reduced rates of carbon loss in the presence of O2 plasma, radicals or VUV+O2 compared to films with terminal carbon groups due to fundamentally different patterns of Si-C bond scission. The results demonstrate the potential of backbone carbon low-k films to resist plasma induced damage.
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Marshall, Gillian E. "Thermal annealing and superconductivity in Zr based metallic glasses." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65501.
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Shrestha, Kiran (Engineer). "Electrical Conduction Mechanisms in the Disordered Material System P-type Hydrogenated Amorphous Silicon." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc700106/.
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The electrical and optical properties of boron doped hydrogenated amorphous silicon thin films (a-Si) were investigated to determine the effect of boron and hydrogen incorporation on carrier transport. The a-Si thin films were grown by plasma enhanced chemical vapor deposition (PECVD) at various boron concentrations, hydrogen dilutions, and at differing growth temperatures. The temperature dependent conductivity generally follows the hopping conduction model. Above a critical temperature, the dominant conduction mechanism is Mott variable range hopping conductivity (M-VRH), where p = ¼, and the carrier hopping depends on energy. However, at lower temperatures, the coulomb interaction between charge carriers becomes important and Efros-Shklosvkii variable hopping (ES-VRH) conduction, where p=1/2, must be included to describe the total conductivity. To correlate changes in electrical conductivity to changes in the local crystalline order, the transverse optical (TO) and transverse acoustic (TA) modes of the Raman spectra were studied to relate changes in short- and mid-range order to the effects of growth temperature, boron, and hydrogen incorporation. With an increase of hydrogen and/or growth temperature, both short and mid-range order improve, whereas the addition of boron results in the degradation of short range order. It is seen that there is a direct correlation between the electrical conductivity and changes in the short and mid-range order resulting from the passivation of defects by hydrogen and the creation of trap states by boron. This work was done under the ARO grant W911NF-10-1-0410, William W. Clark Program Manager. The samples were provided by L-3 Communications.
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Duque, Jose Gerivaldo dos Santos. "Magnetoimpedância gigante linear e não-linear em ligas amorfas." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278277.
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Orientador: Marcelo Knobel<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin<br>Made available in DSpace on 2018-08-04T08:20:32Z (GMT). No. of bitstreams: 1
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Previous issue date: 2005<br>Resumo: Não informado<br>Abstract: Not informed.<br>Doutorado<br>Física da Matéria Condensada<br>Doutor em Ciências
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Maldei, Michael. "A study of the suitability of amorphous, hydrogenated carbon (a-C:H) for photovoltaic devices." Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1175022667.
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Manoharan, Krishna. "Design and Analysis of High-Q, Amorphous Microring Resonator Sensors for Gaseous and Biological Species Detection." Ohio : Ohio University, 2009. http://www.ohiolink.edu/etd/view.cgi?ohiou1237489189.
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Malaguti, Vilmar dos Santos. "Reuso de água e resíduos gerados pela lavagem de caminhões betoneiras: análise do efeito na resistência à compressão de concreto usinado." Universidade Tecnológica Federal do Paraná, 2016. http://repositorio.utfpr.edu.br/jspui/handle/1/1886.
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O objetivo deste trabalho é analisar a resistência à compressão do concreto e seus possíveis efeitos com o reuso da água e dos resíduos de lavagens dos caminhões betoneiras. A revisão bibliográfica sobre o assunto proposto foi estudado e discutido em países como Grécia, Taiwan, Alemanha, Itália, Cingapura e outros, o que serviu de apoio e reforço para este trabalho. O método para analisar a resistência à compressão foi de comparação entre uma amostra controle (traço padrão de 30 MPa) e amostras com diferentes composições. O resultado de cada amostra foi diferente em função de sua composição, no entanto, pode-se afirmar ganho econômico na ordem de 20,21 R$/m3, além da resistência à compressão ser maior que 90% da amostra controle. As análises realizadas nas amostras através de DRX, MEV e EDS comprovaram que não houve síntese de novos minerais, somente pequenas quantidades (menor do que os limites de detecção do método de DRX) de alumino-silicatos e quartzo dissolvidos que foram sintetizados em novos minerais cristalinos, que podem ser atribuídos como substancias amorfas em estado sol-gel. Com o resultado observa-se que o reuso da água de lavagem dos caminhões betoneiras não interferem na resistência à compressão de novos concretos, assim como o resíduo de lavagem que não apresentou nenhum elemento diferente do composto no cimento, também não interfere na resistência à compressão de novos concretos, desde que haja controle da água presente.<br>The objective of this study is to analyze the strength of concrete compression and its possible effects on water reuse and waste washes of concrete mixer trucks. The literature review on the proposed subject was studied and discussed in countries like Greece, Taiwan, Germany, Italy, Singapore and others, which served as support and reinforcement for this work. The method for analyzing the compressive strength was compared between the control sample (standard stroke 30 MPa) and samples with different compositions. The result of each sample was different depending on their composition, however, it can be stated economic gain on the order of 20,21 R$/m3, in addition to the compressive strength is greater than 90% of the control sample. The samples were analyzed by DRX, MEV and EDS showed that there was no synthesis of new mineral, only small amounts (lower than the detection limits of the DRX method) dissolved alumino-silicates and quartz which have been synthesized into new mineral crystalline, which can be assigned as amorphous substances in sol-gel state. With this result it was observed that the reuse of the concrete mixer trucks washing water does not interfere with the compressive strength of new concrete, as well as the washing residue which presented no different element of the compound in cement, does not interfere with the compressive strength new concrete, provided that control of the water present.
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Dehlinger, Nicolas. "Étude des performances d'une machine à flux transverse à noyaux ferromagnétiques amorphes." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24934/24934.pdf.
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Parmi les différentes structures de machines électriques existantes, les machines à flux transverse (MFT) sont reconnues pour leur fort couple massique et volumique. Malgré cet avantage, leur complexité et leur coût de fabrication élevés font que ce type de machine ne dépasse que rarement le stade de prototype. De plus, d’importantes pertes fer dues à des fréquences de fonctionnement élevées limitent encore l’utilisation de ces machines aux applications basse vitesse et fort couple : la MFT est alors principalement utilisée dans des dans les aérogénérateurs à attaque directe et dans certaines applications de traction électrique (bus, automobile, tram, navire, …).
Le travail présenté dans ce mémoire s’inscrit dans le cadre du développement d’une nouvelle configuration de MFT : la MFT à griffe ou claw-pole, à stator hybride. Grâce à l’utilisation combinée de tôles électriques et de poudre de fer au stator de la machine, les pertes fer de cette configuration de MFT sont considérablement réduites et sa fabrication grandement simplifiée.
Le concept de stator hybride peut être exploité pour réduire les pertes fer de la MFT encore davantage, par l’emploi de matériaux possédant des propriétés magnétiques supérieures à celles des matériaux actuellement utilisés au stator de la machine. L’effet de la substitution des noyaux de tôles électriques au stator par des noyaux fabriqués à partir de matériaux amorphes est étudié dans ce mémoire. Des mesures expérimentales de pertes fer permettent, dans un premier temps, de prouver la réduction des pertes totales d’une MFT claw-pole à stator hybride monopolaire utilisant des noyaux amorphes. Dans un second temps, des simulations par éléments finis couplées à des résultats expérimentaux montrent l’augmentation du rendement d’une MFT complète à noyaux amorphes et le maintien de ce dernier à un niveau élevé à des fréquences de fonctionnement supérieures à 400 Hz.<br>Transverse flux machines (TFM) are known for their excellent torque-to-mass and torque-to-volume ratio when compared to conventional machines. Despite this advantage, they have some serious shortcomings like complex construction and high cost, explaining why TFM that can be found in the literature are usually only prototypes. Moreover, the TFM shows a dependence of its force density upon its pole pitch and airgap thickness, which leads to high electrical frequencies and thus to high core losses. For all these reasons, this type of machine could be considered in high-torque low-speed applications such as wind turbines or electrical traction drives.
The work presented in this document contributes to the development of a new TFM configuration: the claw-pole TFM with hybrid stator (CPTFMHS). Such a stator built from a combination of Fe-Si laminations and powdered iron (SMC), enables reducing iron losses significantly and improving the ease of manufacturing of the machine.
The concept of the hybrid stator can be further developed by using new magnetic materials with lower specific losses. The substitution of Fe-Si laminations by amorphous cores in the stator of the CPTFMHS is studied in this work and presented here. Experimental measurements are conducted on a one-pole pair CPTFMHS machine with an amorphous core: the results show a reduction of the total iron losses, thus proving benefits of amorphous cores used in the machine. Finite element simulations coupled with experimental measurements lead to the following conclusion: the efficiency of a CPTFMHS machine can be maintained to a high level at frequencies above 400 Hz, thanks to the use of amorphous cores, which may not be possible with Fe-Si laminations.
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Mpingi, Wilfred Mbiombi. "Structural, electrical and electronic properties of diamond like carbon (DLC) and carbon-based materials." Thesis, 2014.
Find full textAbstract:
this work, we have used the diamond-like carbon (DLC) also known as hydrogenated amorphous carbon (a-C:H), silicon doped DLC (a-C:H:Si) thin films deposited by the plasma enhanced chemical vapour deposition (PECVD) process on silicon substrate and studied their structural, electrical and electronic properties. The DLCs films were prepared at different applied bias voltage (Vb) starting from 100V to 600V; whereas the silicon is doped with DLC thin films using tetramethysilane (TMS) as a precursor at different standard centimetre cube per minute (sccm). In addition nitrogen doped amorphous carbon (a-C:Nx) thin films prepared by pulsed laser deposition (PLD) process and studied their different properties. Different nitrogen concentration (at.%) of a-C:Nx thin films were deposited on silicon substrate using nitrogen-gas as a precursor. The thicknesses of all thin films were ~15015 nm controlled and monitored during deposition process. Raman spectroscopy of these thin films was measured by using two different laser excitation wavelengths viz 488 nm and 647 nm respectively. The microstructure and electronic properties of these samples were investigated by Raman spectroscopy and the electrical property was studied by current-voltage (I-V) characteristics. Finally, a correlation among the electrical properties, electronic properties and micro-structure properties were established based on their sp3 and sp2 concentration in the thin film structure.
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Safarik, Douglas Joseph. "Crystallization of amorphous solid films." 2003. http://wwwlib.umi.com/cr/utexas/fullcit?p3116175.
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McClure, Sean Michael. "Transport mechanisms in nanoscale amorphous solid water films." Thesis, 2006. http://hdl.handle.net/2152/2575.
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"preparation of bulk amorphous Pd₄₀Ni₄₀P₂₀ alloys by compaction." 2001. http://library.cuhk.edu.hk/record=b5890792.
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Ma Lai Ching = 利用熱壓法制備塊体非晶態Pd₄₀Ni₄₀P₂₀合金 / 馬勵貞.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.<br>Includes bibliographical references (leaves 51).<br>Text in English; abstracts in English and Chinese.<br>Ma Lai Ching = Li yong re ya fa zhi bei kuai ti fei jing tai Pd₄₀Ni₄₀P₂₀ he jin / Ma Lizhen.<br>Acknowledgements --- p.i<br>Abstract --- p.ii<br>Chapter Chapter 1 --- Introduction --- p.1<br>Chapter 1.1 --- Introduction to Metallic Glass --- p.1<br>Chapter 1.2 --- Applications of Metallic Glass --- p.2<br>Chapter 1.3 --- Solidification Process --- p.3<br>Chapter 1.4 --- Some Production Methods of Bulk Glassy Alloys --- p.10<br>Chapter 1.5 --- Another Production Methods: Powder Consolidation --- p.11<br>Chapter 1.6 --- Flaws of the as-Compacted Materials --- p.16<br>Chapter 1.7 --- A Solution --- p.17<br>References --- p.20<br>Figures --- p.22<br>Chapter Chapter 2 --- Experimental --- p.31<br>Chapter 2.1 --- Production of Pre-Compacted Bulk Metallic Glass --- p.31<br>Chapter 2.2 --- Handling of Bulk Glass Before Compaction --- p.34<br>Chapter 2.3 --- Compaction Process --- p.35<br>Chapter 2.1 --- Sample Analysis --- p.37<br>Figures --- p.40<br>Chapter Chapter 3 --- Mechanism of fusion of bulk metallic glasses --- p.45<br>Abstract --- p.45<br>References --- p.51<br>Table --- p.52<br>Figures --- p.53
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Tiwari, Rashmi Satyanarayan. "A new determination of molecular mobility in amorphous materials." 2008. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051222.
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"Crystallization kinetics of amorphous nanostructured materials =: 非晶納米結構材料的結晶動力學". 1998. http://library.cuhk.edu.hk/record=b5889731.
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Ngai Hau Wai.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.<br>Includes bibliographical references.<br>Text in English; abstract also in Chinese.<br>Ngai Hau Wai.<br>Acknowledgements --- p.ii<br>Abstract --- p.iii<br>Chapter Chapter 1: --- Introduction --- p.1<br>Chapter 1.1 --- History of nanomaterials --- p.1<br>Chapter 1.2 --- Application and properties of nanomaterials --- p.2<br>Chapter 1.3 --- Thermodynamic of a binary system --- p.4<br>Chapter 1.4 --- Nucleation and growth --- p.5<br>Chapter 1.5 --- Spinodal decomposition --- p.7<br>References --- p.10<br>Figures --- p.11<br>Chapter Chapter 2: --- Experimental setup and techniques --- p.21<br>Chapter 2.1 --- How to achieve high undercooling? --- p.21<br>Chapter 2.2 --- Preliminary steps --- p.22<br>Chapter 2.2.1 --- Preparation of dehydrated B203 --- p.22<br>Chapter 2.2.2 --- Preparation of the apparatus --- p.23<br>Chapter 2.2.3 --- Preparation of Ni2P --- p.23<br>Chapter 2.2.4 --- Alloying --- p.23<br>Chapter 2.3 --- Experiment --- p.24<br>Chapter 2.3.1 --- Preparation of pure glass --- p.24<br>Chapter 2.3.2 --- Anneal the glass pieces at different temperature for 30 minutes… --- p.24<br>Chapter 2.4 --- Investigation --- p.25<br>Chapter 2.4.1 --- Thermal Properties --- p.25<br>Chapter 2.4.2 --- TEM observation --- p.25<br>References --- p.27<br>Figures --- p.28<br>Chapter Chapter 3: --- Crystallization kinetics of amorphous nanostructured materials --- p.32<br>Abstract --- p.32<br>Chapter 3.1 --- Introduction --- p.33<br>Chapter 3.2 --- Experimental --- p.34<br>Chapter 3.3 --- Results and Discussion --- p.35<br>References --- p.41<br>Figures --- p.42
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"Formation and crystallization of amorphous nanostructured materials =: 非晶納米材料的形成與結晶". 1998. http://library.cuhk.edu.hk/record=b5889706.
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by Leung Ching Chuen.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.<br>Includes bibliographical references (leaf 47).<br>Text in English; abstract also in Chinese.<br>by Leung Ching Chuen.<br>Acknowledgments --- p.ii<br>Abstract --- p.iii<br>Chapter Chapter 1 --- Introduction --- p.1<br>Chapter 1.1 --- Expansion of the Mesoscopic World --- p.2<br>Chapter 1.2 --- Nanostructured Materials --- p.3<br>Chapter 1.3 --- A New Age --- p.4<br>Chapter 1.4 --- """Flaws"" of the New Age" --- p.5<br>Chapter 1.5 --- Phase Transformation --- p.7<br>Chapter 1.6 --- Nucleation and Growth --- p.8<br>Chapter 1.7 --- Spinodal Decomposition --- p.11<br>Chapter 1.8 --- Morphology Change during Spinodal Decomposition --- p.13<br>References --- p.16<br>Figures --- p.17<br>Chapter Chapter 2 --- Experiment --- p.25<br>Chapter 2.1 --- Experimental Preparations --- p.27<br>Chapter 2.1.1 --- Fused Silica Tube Preparation --- p.27<br>Chapter 2.1.2 --- Alloying --- p.27<br>Chapter 2.2 --- Experimental Procedures --- p.28<br>Chapter 2.2.1 --- Fluxing --- p.28<br>Chapter 2.2.2 --- Undercooling --- p.29<br>Chapter 2.3 --- Sample Analysis --- p.30<br>Chapter 2.3.1 --- Surface Analysis --- p.30<br>Chapter 2.3.2 --- Differential Scanning Calorimetry (DSC) --- p.30<br>Chapter 2.3.3 --- Hardness Testing --- p.31<br>Chapter 2.3.4 --- Optical Microscopy --- p.32<br>Chapter 2.3.5 --- Scanning Electron Microscopy (SEM) --- p.32<br>Chapter 2.3.6 --- Transmission Electron Microscopy (TEM) --- p.32<br>Chapter 2.3.7 --- X-ray Powder Diffraction (XPD) --- p.33<br>References --- p.34<br>Figures --- p.35<br>Chapter Chapter 3 --- Mechanism of Bulk Nanostructured Material Formation by Metastable Liquid State Spinodal Decomposition --- p.38<br>Abstract --- p.39<br>References --- p.47<br>Figures --- p.48<br>Chapter Chapter 4 --- Formation of Amorphous Nanostructured Material --- p.57<br>Abstract --- p.58<br>References --- p.66<br>Figures --- p.67<br>Chapter Chapter 5 --- Crystallization Kinetics of Amorphoous Nanostructured Alloy --- p.75<br>Abstract --- p.76<br>References --- p.85<br>Figures --- p.86<br>Chapter Chapter 6 --- Conclusion --- p.101
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Knutson, Christopher C. "The chemistry and device applications of amorphous thin-film interfaces." Thesis, 2011. http://hdl.handle.net/1957/26076.
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Solid-state amorphous materials show amazing promise in thin-film electronics. The interface-to-bulk ratio of thin films makes interfacial chemistries of these systems of utmost importance. Thin films of amorphous metals, dielectrics and semiconductors have novel chemistries that are not only based upon their elemental constituent makeup, but also based upon the method with which the amorphous material is deposited and treated after deposition. The chemical attributes unique to amorphous, thin-film systems are defined primarily through the utilization of solution-processed aluminum oxide phosphate dielectric material and Zr������Cu������Al������Ni������ metal. the chemical findings wrought via the observation of interactions between amorphous metal-dielectric systems are applied to semiconductor/insulator systems to illustrate the use of the same general chemical principles applying to diverse problems. Finally in the appendices, the systems are utilized to create extremely-thin tunneling electronic devices and optical metamaterials as well as innovative classroom material.<br>Graduation date: 2012<br>Access restricted to the OSU Community at author's request from Dec. 13, 2011 - Dec. 13, 2012
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Akin, Minta Carol 1980. "Low-energy electron driven reactions in layered methanol/amorphous solid water films." Thesis, 2008. http://hdl.handle.net/2152/3815.
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Understanding the radiolysis of impure water and resulting reactions is crucial to many fields. Reactions driven by low energy electrons (LEE) are of special interest, as high-energy radiation generates large quantities of these electrons, which then provide the energy for most subsequent reactions. Interfacially located reactions are also of particular interest, both as models for heterogeneously distributed reactions occurring during radiolysis, and in their own right, as radiation-driven reactions at interfaces are responsible for key processes such as corrosion and DNA damage. To study LEE-driven reactions at interfaces, thin-layered films of amorphous solid water (ASW) and methanol were grown under ultra-high vacuum conditions using molecular beam techniques. The films were exposed to a beam of low-energy (100eV or less) electrons, and studied using electron-stimulated desorption (ESD) and temperature programmed desorption (TPD). ESD studies indicated that methanol moves through a water film during deposition at 80 K but not at 50 K. This transport was not seen during thermal annealing, but radiation-induced mixing was observed at all temperatures. Major and minor LEE radiation products of pure methanol films were identified and found to be consistent with previous results. Products of LEE irradiated layered methanol/water films were determined for the first time using ESD and TPD spectra, and found to be limited to H₂, O, O₂, CH₂O, C₂H₆, CO, CO₂, CH₃OCH₃, and CH₃CH₂OH. The effect of adding methanol to an ASW film on the production in ASW of H₂ and O₂ was also examined. The interface created by the addition of CH₃OH to ASW was found to generate H₂ in previously non-reactive regions of the water film by increasing water-water and water-methanol reactions. Radiative mixing of CH₃OH and ASW enhanced this effect, presumably by increasing the region of disrupted H-bonding in the ASW. In contrast, the addition of CH₃OH at low coverages suppressed O₂ production in both unprocessed and preprocessed ASW layers. Modeling indicates that methanol scavenging of the O₂ precursor OH and of the reaction-driving electrons is responsible for this reduction in O₂ signal.
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You, Yumin. "Modulation of molecular mobility in sucrose-based amorphous solids detected by phosphorescence of erythrosin B." 2007. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.17034.
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Valanathan, Munsami. "Experimental investigation and theoretical analysis of the structural relaxation in amorphous Fe40Ni40B20." Thesis, 1998. http://hdl.handle.net/10413/4630.
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Amorphous metallic alloys are produced by a variety of techniques some of which involve rapid solidification of the alloying constituents. In these methods the solidification occurs so rapidly that the atoms are frozen-in and partially retain their liquid configuration. There are clear structural and other indications from their various properties that amorphous metallic alloys possess short range order but lack long range order. In general, amorphous alloys are not in a thermodynamic equilibrium state and, therefore, relax structurally whenever atoms attain an appreciable mobility. Associated with structural relaxation, many physical properties change; some significantly and others only slightly. Relaxation experiments in amorphous metallic alloys often display approximate In(t) kinetics which can be understood in terms of various models. In the present work the model by Primak (1955), for which the kinetic behaviour of a system depends on processes that are distributed over a range of activation energies, is used as a basis for further development. The Primak model allows, in principle, for the identification of the order of
the relaxation reaction and for the determination of an initial activation energy spectrum Po(Єo), where Єo is a characteristic activation energy. Although the model provides for a qualitative explanation of the In(t) law, it has no predictive power as to the quantitative
changes accompanying the various relaxing properties. Furthermore, an estimation of Po( Єo), inferred from various isothermal annealing procedures, reveals the approximate shape but does not fix its location on the activation energy axis. These shortfalls are attributed to complications in the frequency factor v, inherent to the Primak model. Also, the Primak model does not include consideration of the entropy involved in a 'configurational jump' of any particular atom during the relaxation process. Inclusion of the configurational entropy through the frequency factor v, in the present treatment, leads to a 'relaxation equation'. Structural relaxation measurements of density (in practice length - from which density can be approximately inferred) and electrical resistivity, in an Fe4oNi40B20 alloy, have been obtained and fitted to this relaxation equation. The fitting parameters are
found, within experimental error, to be the same for both length and resistivity relaxation. The initial activation energy spectrum Po(Єo), as inferred from the fits, over the energy range 1.4 to 2.0 eV, reveals roughly three regimes, namely below 1.5 eV, from 1.5 to 1.8 eV, and above 1.8 eV, respectively, over which the initial activation energy spectrum Po( Єo) assumes different approximately constant values. Previous treatments have, however, implicitly assumed that Po( Єo) is constant throughout a temperature range over which In(t) kinetics is observed. The behaviour observed in this work is associated with
the intrinsic relaxation mechanism involving consecutive diffusion of the metallic and metalloid atoms, respectively. A configurational entropy change inferred from this work is found to be negative as a consequence of contraction of the spread-out free volume resulting from thermal fluctuations. Within the framework of the 'present model', other related behaviour of amorphous metallic alloys, including the glass transition, crystallization and diffusion, are discussed. Where direct comparison between theory and experiment is possible for the various observed phenomena, the agreement is good and shows an overall consistency in our approach. Finally, the analysis considered here gives an expression which can be easily
used to make quantitative predictions about the experimental relaxation behaviour. An immediate understanding of some of the main features of experimental data on relaxation can, therefore, be obtained through application of the present model.<br>Thesis (Ph.D.)-University of Natal, Durban, 1998.
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"Preparation of bulky ferromagnetic Fe₈₀P₁₃C₇ amorphous alloy." 2000. http://library.cuhk.edu.hk/record=b5890327.
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Chan Fu-wai = 非晶態鐵磁性鐵-磷-碳合金的製作 / 陳輔偉.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.<br>Includes bibliographical references.<br>Text in English; abstracts in English and Chinese.<br>Chan Fu-wai = Fei jing tai tie ci xing tie-lin-tan he jin de zhi zuo / Chen Fuwei.<br>Acknowledgments --- p.i<br>Abstract --- p.ii<br>Table of Content --- p.iv<br>Chapter Chapter 1: --- Introduction --- p.1<br>Chapter 1.1 --- Nucleation --- p.1<br>Chapter 1.1.1 --- Homogenous nucleation --- p.1<br>Chapter 1.1.2 --- Heterogeneous nucleation --- p.4<br>Chapter 1.2 --- The crystal growth --- p.5<br>Chapter 1.2.1 --- The solid-liquid interface --- p.5<br>Chapter 1.2.2 --- Lateral growth --- p.6<br>Chapter 1.2.3 --- Continuous growth --- p.6<br>Chapter 1.3 --- Non-equilibrium process --- p.8<br>Chapter 1.3.1 --- Reduction of impurities --- p.8<br>Chapter 1.3.2 --- Suppression of crystal growth --- p.8<br>Chapter 1.4 --- The change in metallurgy --- p.9<br>Chapter 1.4.1 --- The metallic glass --- p.9<br>Chapter 1.4.2 --- The properties of glass --- p.10<br>Chapter 1.4.3 --- The development of amorphous alloy --- p.11<br>Chapter 1.5 --- Preparation methods of amorphous alloy --- p.12<br>Chapter 1.6 --- The criterion of glass formation --- p.14<br>Chapter 1.7 --- The study of this project --- p.15<br>Reference --- p.16<br>Figure --- p.19<br>Chapter Chapter 2: --- Experiment --- p.36<br>Chapter 2.1 --- Preparation --- p.36<br>Chapter 2.2 --- Experimental procedure --- p.37<br>Chapter 2.3 --- Sample analysis --- p.38<br>Reference --- p.41<br>Figure --- p.42<br>Chapter Chapter 3: --- The formation of bulk ferromagnetic Fe-P-C amorphous alloy --- p.45<br>Abstract --- p.45<br>Introduction --- p.46<br>Experiment --- p.47<br>Result --- p.48<br>Reference --- p.49<br>Figure --- p.52<br>Chapter Chapter 4: --- Compaction of bulk ferromagnetic Fe-P-C amorphous alloy --- p.57<br>Abstract --- p.57<br>Introduction --- p.58<br>Experiment --- p.58<br>Result --- p.60<br>Reference --- p.61<br>Figure --- p.62<br>Chapter Chapter 5: --- Conclusion --- p.65
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Matteucci, Michal Elizabeth 1977. "Highly supersaturated aqueous solutions by design of amorphous pharmaceutical nanoparticles." 2007. http://hdl.handle.net/2152/16019.
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For 40% of currently discovered drugs which are poorly water soluble, engineering amorphous nanoparticles with rapid dissolution and enhanced solubility can improve their absorption. Antisolvent precipitation by mixing organic drug solutions with aqueous solutions produced sub-300 nm amorphous nanoparticle dispersions. Polymeric stabilizers increased the nucleation rate by lowering the interfacial tension and adsorbed to particle surfaces to inhibit growth by condensation and coagulation. An increase in the stabilizer concentration decreased the average particle size until reaching a threshold where the particles were < 300 nm for the poorly water soluble drug, itraconazole. The amorphous itraconazole nanoparticle dispersions dissolved at pH 1.2 to produce high supersaturation levels up to 90-times the equilibrium solubility. The supersaturation increased with particle curvature, as described qualitatively by the Kelvin equation. A thermodynamic analysis indicated the stabilizer maintained amorphous ITZ in the solid phase with a fugacity 90-times the crystalline value, while it did not influence the activity coefficient of ITZ in the aqueous phase. Recovery of the amorphous nanoparticles from water was achieved by adding salt to desolvate the polymeric stabilizers and flocculate the particles, which could then be rapidly filtered. The flocculation under constant particle volume fraction produced open flocs which were redispersible in water to their original ~300 nm size, after filtration and drying. Amorphous particles were preserved, as flocs were formed below the drug's glass transition temperature. After flocculation/filtration, medium surface area (2-5 m²/g) particles dissolved rapidly in pH 6.8 buffer with 0.17% surfactant to an unusually large supersaturation up to 17, comparable to that for high surface area (13-36 m²/g) particles. However, the decay in supersaturation was much slower for the medium surface area particles, as the smaller excess surface area of undissolved particles produced slower nucleation and growth from solution. In contrast, the maximum supersaturation was far lower for more conventional low surface area solid dispersions of drug in polymers, because of crystallization of undissolved solid during slow dissolution. The ability to design the particle morphology to manipulate the level in supersaturation in pH 6.8 media, offers new opportunities in raising bioavailability in gastrointestinal delivery.<br>text
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"Amorphous phase separation in a bulk metallic glass of negative heat of mixing." 2012. http://library.cuhk.edu.hk/record=b5549408.
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過去幾十年當中，金屬玻璃（包括塊狀金屬玻璃）中非晶相分離的發生已經成為了一個具有爭議性的課題。一些報告報導在具有負混合熱的Pd-Ni-P合金體系中發生了非晶相分離。然而，有一些報告聲稱相分離不能在Pd-Ni-P非晶合金中被觀察到。文獻分析表明，困難在於缺乏直接的實驗證據。<br>為了解決這個難題，示差掃描量熱儀、高分辨電子顯微鏡、掃描透射模式下的高角環射暗場相、以及能量色散X射線光譜儀等檢測儀器在我們實驗當中被使用。同時為了清楚展示非晶相分離反應，在過冷Pd₄₁.₂₅Ni₄₁.₂₅P₁₇.₅熔體被冷卻為固態非晶樣品之前引入了中間熱退火處理。<br>實驗研究了三種經由不同路徑製備的A、B、C型號樣品。結果表明在非晶/液態Pd₄₁.₂₅Ni₄₁.₂₅P₁₇.₅合金中可能存在獨特的短程有序結構，它會導致相分離的發生。同时研究發現，在大約625 K，調幅分解的持續時間的下限大概是200 s。調幅分解的時間常數R在大約625 K 下為0.002 s⁻¹。三种类型样品在不同的溫度下被退火從而獲得部分的結晶。A型號和B型號具有相似的行為。在低溫下，圓形的核心首先形成，接著發生共晶反應。在高溫下，出現了一種形狀為立方體的析出相。在C型號的樣品當中，核心和立方的析出物同時被發現。但是核心的成分分佈與A和B型號中出現的不同。同時，隨著退火時間的加長形核的數量也具有獨特的行為表現。作為對比，Pd₄₀Ni₄₀P₂₀塊狀金屬玻璃的結晶行為也被展開了研究。同樣的，以形成核心開始，但是它的成分分佈異於A和B型號的樣品。<br>Amorphous phase separation in metallic glass (including bulk metallic glass) has been a controversial issue in the past several decades. There are reports saying that amorphous phase separation occurs in Pd-Ni-P, which has a negative heat of mixing among its constituent elements. However, there are also as many reports claiming that phase separation is absent in amorphous Pd-Ni-P alloys. The lack of direct experimental evidence makes the issue to be difficult to be resolved.<br>To solve this problem, differential scanning calorimetry (DSC), high resolution transmission electron microscopy (HRTEM), high angle annular dark field (HAADF) in scanning transmission electron microscopy, and energy dispersive X-ray spectroscopy (EDX) have been employed. Intermediate thermal annealing is introduced before an undercooled Pd₄₁.₂₅Ni₄₁.₂₅P₁₇.₅ melt is cooled down to become a solid amorphous specimen.<br>A-type, B-type, and C-type specimens of composition, Pd₄₁.₂₅Ni₄₁.₂₅ P₁₇.₅, have been prepared via three different cooling paths. It was found that amorphous phase separation indeed occurs in C-type specimens. Results suggest that there may be unique short range orders in amorphous/liquid Pd₄₁.₂₅Ni₄₁.₂₅P₁₇.₅, which are responsible for the phase separation. Experimental arrangements were made to study the occurrence of spinodal reaction in undercooled molten Pd₄₁.₇₅Ni₄₁.₇₅P₁₇.₅ alloys as a function of time. The lower bound of the duration of the spinodal decomposition at a temperature of {U+2248}625 K is about 200 s and the time constant R of the spinodal decomposition at a temperature of {U+2248}625 K is 0.002 s⁻¹.<br>A-type and B-type specimens have similar crystallization behavior. At low temperature, it starts with the formation of a spherical core and then eutectic crystallization takes over. At higher temperatures, an additional phase in the shape of a cube appears. In annealed C-type specimens, cores and cubic precipitates are also found. However, the composition profile of the cores is different and the number of nucleation events versus time has peculiar characteristics. The crystallization behavior of Pd₄₀Ni₄₀P₂₀ BMG was studied for comparison. It again starts out with the formation of a core, but with a composition profile different from those of A-type and B-type specimens.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Lan, Si = 對於具有負混合熱的塊狀金屬玻璃非晶相分離的研究 / 蘭司.<br>Thesis (Ph.D.)--Chinese University of Hong Kong, 2012.<br>Includes bibliographical references.<br>Abstract also in Chinese.<br>Lan, Si = Dui yu ju you fu hun he re de kuai zhuang jin shu bo li fei jing xiang fen li de yan jiu / Lan Si.<br>Abstract of thesis --- p.i<br>Acknowledgements --- p.v<br>List of Tables --- p.x<br>List of Figures --- p.xi<br>Chapter Chapter 1 --- Introduction and literature review --- p.1<br>Chapter 1.1 --- Introduction to metallic glasses --- p.1<br>Chapter 1.1.1 --- Background of metallic glasses --- p.1<br>Chapter 1.1.2 --- Glass transition --- p.2<br>Chapter 1.1.3 --- The undercooling of liquids --- p.3<br>Chapter 1.1.4 --- Crystal nucleation and growth in liquids --- p.3<br>Chapter 1.1.4.1 --- Crystal Nucleation in liquids --- p.3<br>Chapter 1.1.4.2 --- Crystal growth in liquids --- p.5<br>Chapter 1.1.4.3 --- TTT diagram --- p.6<br>Chapter 1.1.4.4 --- Crystallization in metallic glasses --- p.6<br>Chapter 1.1.5 --- Glass formation methods and systems --- p.6<br>Chapter 1.1.6 --- Glass forming ability and criteria --- p.8<br>Chapter 1.1.7 --- Properties and applications --- p.9<br>Chapter 1.2 --- The basic theory of phase separation in a binary system --- p.10<br>Chapter 1.2.1 --- Thermodynamic background --- p.10<br>Chapter 1.2.2 --- Solid state phase separation --- p.11<br>Chapter 1.2.2.1 --- A miscibility gap of binary mixture --- p.11<br>Chapter 1.2.2.2 --- Nucleation and growth mechanism --- p.12<br>Chapter 1.2.2.3 --- Spinodal decomposition mechanism --- p.13<br>Chapter 1.2.3 --- Liquid state miscibility gap in a binary system --- p.21<br>Chapter 1.3 --- Literature review for phase separation in metallic glasses --- p.23<br>Chapter 1.4 --- The aim of this thesis --- p.28<br>Figures --- p.30<br>References --- p.39<br>Chapter Chapter 2 --- Experiments and characterization --- p.44<br>Chapter 2.1 --- Introduction and the outline of the experiments --- p.44<br>Chapter 2.2 --- Sample preparation --- p.45<br>Chapter 2.2.1 --- Bulk metallic glasses preparation --- p.45<br>Chapter 2.2.1.1 --- Preparation of clean fused silica tubes --- p.45<br>Chapter 2.2.1.2 --- Weighing --- p.46<br>Chapter 2.2.1.3 --- Alloying --- p.46<br>Chapter 2.2.1.4 --- Fluxing --- p.47<br>Chapter 2.2.2 --- Thermal annealing --- p.49<br>Chapter 2.2.3 --- Specimens preparation for characterization --- p.50<br>Chapter 2.2.3.1 --- Cutting, molding, grinding and polishing --- p.50<br>Chapter 2.2.3.2 --- Etching --- p.51<br>Chapter 2.2.3.3 --- Thinning for TEM foils --- p.51<br>Chapter 2.3 --- Characterization --- p.55<br>Chapter 2.3.1 --- Differential scanning calorimetry (DSC) --- p.55<br>Chapter 2.3.2 --- Scanning electron microscopy (SEM) --- p.55<br>Chapter 2.3.3 --- Transmission electron microscopy (CTEM and HRTEM) --- p.57<br>Chapter 2.3.4 --- High angle annular dark field (HAADF) in Scanning transmission electron microscopy (STEM) --- p.58<br>Chapter 2.3.5 --- Energy dispersive X-ray spectroscopy (EDX) --- p.59<br>Figures --- p.62<br>References --- p.69<br>Chapter 3 --- p.70<br>Chapter 3.1 --- Introduction --- p.70<br>Chapter 3.2 --- Materials and Experimental --- p.73<br>Chapter 3.3 --- Results --- p.75<br>Chapter 3.3.1 --- Thermal behaviors of three types of specimens --- p.75<br>Chapter 3.3.2 --- Microstructures of three types of specimens --- p.75<br>Chapter 3.3.2.1 --- A-type specimens --- p.75<br>Chapter 3.3.2.2 --- B-type specimens --- p.76<br>Chapter 3.3.2.3 --- C-type specimens --- p.76<br>Chapter 3.4 --- Discussion --- p.78<br>Chapter 3.5 --- Conclusions --- p.79<br>Chapter 3.6 --- Afterward --- p.79<br>Figures --- p.80<br>References --- p.89<br>Chapter Chapter 4 --- The time constant of the spinodal decomposition in Pd₄₁.₇₅Ni₄₁.₇₅P₁₇.₅ bulk metallic glasses --- p.92<br>Chapter 4.1 --- Introduction --- p.92<br>Chapter 4.2 --- Materials and experimental --- p.92<br>Chapter 4.3 --- Results --- p.94<br>Chapter 4.3.1 --- Thermal behaviors --- p.94<br>Chapter 4.3.2 --- Microstructures --- p.94<br>Chapter 4.4 --- Discussion --- p.96<br>Chapter 4.5 --- Conclusions --- p.98<br>Figures --- p.100<br>References --- p.123<br>Chapter Chapter 5 --- Crystallization in homogeneous and phase-separated Pd₄₁.₂₅Ni₄₁.₂₅P₁₇.₅ bulk metallic glasses --- p.125<br>Chapter 5.1 --- Introduction --- p.125<br>Chapter 5.2 --- Experiments --- p.126<br>Chapter 5.3 --- Results --- p.128<br>Chapter 5.3.1 --- Low temperature thermal annealing at 613 K with 0≤t{U+2090} ≤ 8 h --- p.128<br>Chapter 5.3.1.1 --- A-type and B-type specimens --- p.128<br>Chapter 5.3.1.2 --- C-type specimens --- p.130<br>Chapter 5.3.1.3 --- Pd₄₀Ni₄₀P₂₀ BMG --- p.132<br>Chapter 5.3.2 --- High temperature thermal annealing --- p.133<br>Chapter 5.3.2.1 --- A-type and B-type specimens --- p.133<br>Chapter 5.3.2.2 --- C-type specimens --- p.135<br>Chapter 5.3.2.3 --- Pd₄₀Ni₄₀P₂₀ BMG --- p.137<br>Chapter 5.4 --- Discussion --- p.137<br>Chapter 5.4.1 --- Formation of spherical cores --- p.138<br>Chapter 5.4.1.1 --- A-type and B-type Pd₄₁.₇₅Ni₄₁.₇₅P₁₇.₅ specimens --- p.138<br>Chapter 5.4.1.2 --- C-type Pd₄₁.₇₅Ni₄₁.₇₅P₁₇.₅ specimens --- p.139<br>Chapter 5.4.1.3 --- Pd₄₀Ni₄₀P₂₀ BMG --- p.140<br>Chapter 5.4.2 --- Formation of cubic precipitates --- p.141<br>Tables --- p.142<br>Figures --- p.144<br>References --- p.188<br>Chapter Chapter 6 --- Conclusions --- p.190<br>Bibliography --- p.192
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Hsu, Lung-chern, and 許榮宸. "Calculation and Conformatuonal Analysis of Starburst Amorphous TPA-derived Substances for Organic Light Emitting Diode(OLED)." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/06785960541502084906.
Full textAbstract:
碩士<br>國立成功大學<br>化學系專班<br>96<br>We used DFT B3LYP/6-31g*method to calculate TDATA(4,4'4"-tris (diphenylamino)triphenyl) and TDAB(1,3,5-tris-(diphenylamine)benzene) TDAPB(1,3,5-tris(4-diphenylaminophenyl)benzene.the main difference in its certre unit,TDATA regards atom of nitrogen as the centre.TDAPB and TDAB regards phenyl ring as the centre.TDAPB and TDAB difference lie in the centre phenyl ring connects triphenylamine and diphenylamine.In the energy level that these starburst amorphous molecular appear high HOMO and ionization potential is TDAB>TDAPB>TDATA.connect as it methyl and fluoro substituent on the ortho meta and para position is it connect fluoro substituent their IP will increase and meta>para>ortho.connect methyl substituent their TDATA and TDAPB IP will decrease and ortho>meta>para.TDAB will increase on the ortho and it will decrease on the meta and para(meta>para).In the conformatios that neutral molecule of starburst amorphous molecular that its TPA structure moiety bond length is 1.4193~1.4231A0 and dihedral angle is 69~720. because of three-dimensional obstacle connect methyl or fluoro substituent bond length and dihedral angle can produce change on the ortho position.Analyse the respect in the density of charge ,we is it kown by Mulliken charge density all nitrogen atom of neutral molecule of starburst amorphous molecular bring negative charge its value distribute -0.65~ -0.66 , and phenyl ring bring positive charge its value distribute 0.21~0.22 and phenyl ring can add get intoing with figure of atom of nitrogen,connect as it methyl and fluoro substituent and substituent figure can not influence above-mentioned nature on the ortho meta and para position.And while distributing by setting up the Mulliken charge density ,cation molecule and the neutral molecule that amount of difference distributed of charge are right compared with MO of the molecule,we can prove the charge is transmitted that the route is distributed in the HOMO area of the cation molecule from the HOMO area of the neutral molecule .
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Sheppard, Charles Johannes. "Structural and optical characterization of Si:H and ZnO." Thesis, 2008. http://hdl.handle.net/10210/1365.
Full textAbstract:
M.Sc.<br>Thin film solar cell devices based on amorphous silicon absorber films are promising candidates for the efficient conversion of sunlight into useable, cheap electrical energy. However, typical device structures are rather complex and consist of semiconductor/metal contacts as well as a complicated p-i-n junction. Against this background, the present study focussed on the optimization of certain key components of the device, including the transparent conductive oxide, amorphous silicon absorber layers and substrate/metal structures. These thin films were deposited by direct current (DC) magnetron sputtering and radio frequency (RF) capacitativecoupled gas discharge. In each case, a systematic study was conducted in which all the relevant processing parameters were varied over a broad range. The material quality of the respective films was subsequently correlated against the growth parameters. In the case of DC magnetron sputtered ZnO, w hich is generally used as a transparent conductive oxide in the device structure, the material quality were critically influenced by geometric orientation of the sample with respect to the target, the substrate-target distance, deposition power, working pressure and substrate temperature. Optimum structural, optical and electrical properties were obtained in the case of samples deposited at an angle of 80° with respect to the surface of the target. Bombardment damage was to a large extent prevented when the samples were placed at a vertical substrate-to-target distance of 70 mm, 75 mm away from the center zone of the plasma. The optimum substrate temperature, deposition power and working pressure was experimentally found to be 100°C; 600 mW/cm2 and 5.25 ´ 10-3 Torr, respectively. The structural features of the substrates influenced the morphology and optical properties of the DC sputtered metallic films. In general, the surface roughness increased when the glass substrates were replaced by kapton. The glass/silver structures were characterized by relatively smooth surface morphologies, while glass/aluminium films exhibited spike-like growth features. The material properties of intrinsic amorphous silicon were influenced by the RF power, substrate temperature and deposition pressure. A systematic study revealed optimum structural, optical and electrical properties at depositions powers around 43 mW/cm2, substrate temperatures close to 200°C and deposition pressures in the order of 500 mT.<br>Professor V. Alberts
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Cowell, E. William III. "Electronic device and nanolaminate application of amorphous metal thin films." Thesis, 2012. http://hdl.handle.net/1957/29124.
Full textAbstract:
The objective of this dissertation is to develop amorphous metal thin films (AMTFs)
for two-terminal electrical device and nanolaminate applications. Two AMTFs, ZrCuAlNi
and TiAl, are investigated in both two-terminal electrical device and nanolaminate applications.
Material properties including composition, atomic order, surface morphology, surface
potential, and electrical resistivity are explored. Application of AMTFs as electrodes in
tunneling MIM diodes leverages the ultra-smooth AMTF surface morphology which results
from the amorphous atomic order of AMTFs. Analysis methodologies using tunneling MIM
diode I-V characteristics are described. A methodology used to estimate potential barrier
heights is applied to tunneling MIM diode with differing lower electrode material, upper
electrode material and upper electrode deposition technique. A second methodology used to
estimate relative tunneling MIM diode insulator thickness is also presented. The presented
I-V characteristic analysis methodologies illustrate that tunneling MIM diodes fabricated
with AMTF lower electrodes possess tunable I-V characteristics. Nanolaminates are layered
materials fabricated with alternating dissimilar thin-film layers. The flexibility of AMTF
nanolaminates is illustrated through the presentation of amorphous metal/oxide nanolaminates
fabricated with differing AMTFs and aqueous solution deposited oxides. TEM and
XPS depth profile analysis of realized nanolaminates are presented. The optical dielectric
response of ZrCuAlNi/aluminum phosphate oxide (AlPO) and TiAl/AlPO nanolaminates are
evaluated through polarized reflectance measurements and effective medium theory. The optical
dielectric response of the nanolaminates differ from the optical dielectric response of
the component layers. ZrCuAlNi/AlPO and TiAl/AlPO nanolaminates therefore satisfy the
definition of metamaterials.<br>Graduation date: 2012<br>Access restricted to the OSU Community at author's request from May 9, 2012 - May 9, 2013
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"Preparation and characterization of bulk amorphous and nanostructured iron-40 nickel-40 phosphorus-14 boron-6 alloys." 2002. http://library.cuhk.edu.hk/record=b6073403.
Full textAbstract:
"Apr 2002."<br>The numerals in title is subscript.<br>Thesis (Ph.D.)--Chinese University of Hong Kong, 2002.<br>Includes bibliographical references.<br>Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Mode of access: World Wide Web.<br>Abstracts in English and Chinese.