Dissertations / Theses on the topic 'Amorphous materials'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Amorphous materials.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Harrop, J. D. "Structural properties of amorphous materials." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.603792.
Full textGrazier, Jeffery N. "Characterisation of amorphous pharmaceutical materials." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/12986.
Full textChou, Yu-Jen. "Structural studies of amorphous materials." Thesis, University of Oxford, 2018. http://ora.ox.ac.uk/objects/uuid:0f4885fe-fcaa-4275-a3e8-53881112ae73.
Full textChakraborty, Arnab. "Magnetism of Nanocrystallized Amorphous Fe75B10Si15." Thesis, KTH, Materialvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-107191.
Full textBrunier, Thierry Marcel. "Neutron scattering studies of amorphous materials." Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254171.
Full textMelin, Pontus. "Atomistic Modeling of Amorphous Energetic Materials." Thesis, Uppsala universitet, Molekyl- och kondenserade materiens fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-359778.
Full textPandey, Anup. "Modeling and Simulation of Amorphous Materials." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1479377563495893.
Full textJacques, Jeannette. "Boron diffusion within amorphous silicon materials." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0012805.
Full textDinda, Guru Prasad. "Nonequilibrium processing of amorphous and nanostructured materials." Karlsruhe FZKA, 2006. http://nbn-resolving.de/urn:nbn:de:0005-072055.
Full textLuckas, Jennifer. "Electronic transport in amorphous phase-change materials." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00743474.
Full textLowe, A. J. "Photostructural changes and defects in amorphous materials." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355260.
Full textAnwar, M. "Spectroscopic investigations of amorphous complex dielectric materials." Thesis, Brunel University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234036.
Full textLudlam, Jonathan James. "Localisation of the vibrations of amorphous materials." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616024.
Full textCai, Bin. "Model Design and Analysis for Amorphous Materials." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1311192632.
Full textBhattarai, Bishal. "Ab initio Structure Inversion for Amorphous Materials." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1537349044469989.
Full textIgram, Dale J. "Computational Modeling and Characterization of Amorphous Materials." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1564347980986716.
Full textPalma, Joseph John. "X-ray Diffraction Studies of Amorphous Materials." Diss., Temple University Libraries, 2013. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/231213.
Full textPh.D.
This thesis presents a study on two types of X-ray diffraction methodologies applied to the characterization of amorphous materials. The purpose of this study was to assess the feasibility of measuring the diffractive spectrum of amorphous materials by Energy-Dispersive X-ray Diffraction (EDXRD) utilizing Cadmium Zinc Telluride detectors. The total scattering intensity (coherent plus incoherent scatter) spectra precisely measured by high-energy Wide-Angle X-ray Scattering (WAXS) were compared to the EDXRD spectra to determine the level of agreement between the two techniques. The EDXRD spectra were constructed by applying a spectra fusing technique which combined the EDXRD spectra collected at different scattering angles rendering a continuous total scattering spectrum. The spectra fusing technique extended the momentum transfer range of the observed scattered spectrum beyond the limitations of the X-ray source and CZT detection efficiencies. Agreement between the WAXS and fused EDXRD spectra was achieved. In addition, this thesis presents the atomic pair correlation functions and coordination numbers of the first coordination shell for four hydrogen peroxide solutions of varying mass concentrations using Empirical Potential Structural Refinement (EPSR). The results are compared to the state-of-the art ad initio quantum mechanical charge field molecular dynamics (QMCF MD) model of the hydrogen peroxide in solution to support the model's predictions on why hydrogen peroxide is stable in water. The EPSR results using the coherent scattering intensity calculated from the WAXS data set predicts a hydration shell of 6.4 molecules of water surrounding hydrogen peroxide. The results also indicate that hydrogen peroxide is more likely to behave as a proton donor than acceptor. These findings are in agreement with QMCF MD model of aqueous hydrogen peroxide.
Temple University--Theses
Dawson, Janet Caroline. "The electronic properties of granular and amorphous materials." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318097.
Full textIsaeva, Leyla. "Amorphous and crystalline functional materials from first principles." Doctoral thesis, Uppsala universitet, Materialteori, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-260704.
Full textLing, Chan Shek. "Structural studies on silica and other amorphous materials." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385950.
Full textSu, Cheng Ph D. Massachusetts Institute of Technology. "A continuum constitutive model for amorphous metallic materials." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/38928.
Full textIncludes bibliographical references (leaves 153-161).
A finite-deformation, Coulomb-Mohr type constitutive theory for the elastic-viscoplastic response of pressure-sensitive and plastically-dilatant isotropic materials has been developed. The constitutive model has been implemented in a finite element program, and the numerical capability is used to study the deformation response of amorphous nietallic glasses. Specifically, the response of an amorphous metallic glass in tension, compression, strip-bending, and indentation is studied, and it is shown that results from the numerical simulations qualitatively capture major features of corresponding results from physical experiments available in the literature. The response of a Zr-based glass in instrumented plane strain indentation with a cylindrical indenter tip is also studied experimentally. The constitutive model and simulation capability is used to numerically calculate the indentation load versus depth curves, and the evolution of corresponding shear-band patterns under the in-denter. The numerical simulations are shown to compare very favorably with the corresponding experimental results. The constitutive model is subsequently extended to the high homologous temperature regime, and the response of a representative Pd-based metallic glass in tension at various strain rates and temperatures with different pre-annealing histories is studied.
(cont.) The model is shown to capture the major features of the stress-strain response and free volume evolution of this metallic glass. In particular, the phenomena of stress overshoot and strain softening in monotonic experiments at a given strain rate and temperature, as well as strain rate history effects in experiments involving strain rate increments and decrements are shown to be nicely reproduced by the model. Finally, a cavitation mechanism is incorporated in the constitutive model to simulate the failure phenomenon caused by the principal and hydro-static stresses. With the revised theory, the response of a prototypical amorphous grain-boundary is investigated, and the result is later applied to study the deformation and failure behavior of nanocrystalline fcc metals by coupling with appropriate crystal-plasticity constitutive model to represent the grain interior.
by Cheng Su.
Ph.D.
Akamatsu, Hirofumi. "Magnetic Properties of Amorphous Oxides and Related Materials." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/77993.
Full textTse, Shing Chi. "Charge transport and injection in amorphous organic electronic materials." HKBU Institutional Repository, 2007. http://repository.hkbu.edu.hk/etd_ra/821.
Full textSpilsbury, David. "A study of amorphous materials and of multilayer materials by neutron scattering methods." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387793.
Full textCadney, Sean. "Welding and weld repair of nanostructured and amorphous materials." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112561.
Full textJoining of two beveled plates has been accomplished by use of the Cold Spray process. This process uses a converging diverging nozzle to accelerate micron sized powder towards a substrate. The strength of the resulting joint has been compared to freeforms made of powder of the same composition. No significant difference was observed in the mechanical properties between the freeforms and the weldments and examination of the fracture surface showed that the strength of the interface is higher than the strength of the freeform itself.
A weld repair experiment has also been performed where the ElectroSpark Deposition process (ESD) has successfully been used to transfer amorphous material from an electrode to an amorphous substrate without crystallizing either material. This result is of crucial importance as it signifies that these extremely expensive and heat sensitive materials can be repaired when in-service wear causes damage. This process, due to its inherently fast cooling rate, has also successfully been used to transform a crystalline AlCoCe alloy into an amorphous deposit atop both amorphous and crystalline substrates.
Christie, J. K. "Modelling the structural and vibrational properties of amorphous materials." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597664.
Full textMollison, Neil Bruce. "Structural characterisation of amorphous materials by solid state NMR." Thesis, University of Kent, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269106.
Full textMiyajima, Shumpei. "Novel deposition of doped amorphous silicon and related materials." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337909.
Full textPatel, Bhavnita. "Pharmaceutical co-amorphous materials and cocrystals : preparation and analysis." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648098.
Full textBascaran, Julen. "Amorphous Materials as Fast Charging Li-ion Battery Anodes." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1565192878407804.
Full textChowdhury, MD Sadrul. "Computational studies of structure and dynamics in amorphous materials." Thesis, The University of Sydney, 2015. http://hdl.handle.net/2123/13328.
Full textMcComber, Kevin A. "Single-crystal germanium growth on amorphous silicon." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/69792.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 130-136).
The integration of photonics with electronics has emerged as a leading platform for microprocessor technology and the continuation of Moore's Law. As electronic device dimensions shrink, electronic signals encounter crippling delays and heating issues such that signal transduction across large on-chip distances becomes increasingly more difficult. However, these issues may be mitigated by the use of photonic interconnects combined with electronic devices in electronic-photonic integrated circuits (EPICs). The electronics in proposed EPIC designs perform the logic operations and short-distance signal transmission, while photonic devices serve to transmit signals over longer lengths. However, the photonic devices are large compared to electronic devices, and thus the two types of devices would ideally exist on separate levels of the microprocessor stack in order to maximize the amount of silicon substrate available for electronic device fabrication. A CMOS-compatible back-end process for the fabrication of photonic devices is necessary to realize such a three-dimensional EPIC. Back-end processing is limited in thermal budget and does not present a single-crystal substrate for epitaxial growth, however, so high-quality crystal fabrication methods currently used for photonic device fabrication are not possible in back-end processing. This thesis presents a method for the fabrication of high-quality germanium single crystals using CMOS-compatible back-end processing. Initial work on the ultra-high vacuum chemical vapor deposition of polycrystalline germanium on amorphous silicon is presented. The deposition can be successfully performed by using a pre-growth hydrofluoric acid dip and by limiting the thickness of the amorphous silicon layer to less than 120 nm. Films deposited at temperatures of 350° C, 450° C, and 550° C show (110) texture, though the texture is most prevalent in growths at 450° C. Poly-Ge grown at 4500 C is successfully doped n-type in situ, and the grain size of as-grown material is enhanced by lateral growth over a barrier. Structures are fabricated for the growth of Ge confined in one dimension. The growths show faceting across large areas, in contrast to as-deposited poly-Ge, corresponding to enhanced grain sizes. Growth confinement is shown to reduce the defect density as the poly-Ge grows. When coalesced into a continuous film, the material grown from 1 D confinement exhibits a lower carrier density and lower trap density than as-deposited poly-Ge, indicating improved material quality. We measure an increased grain size from as-deposited poly-Ge to Ge grown from ID confinement. Single-crystal germanium is grown at 450° C from confinement in two dimensions. Such growths exhibit faceting across the entire crystal as well as the presence of E3 boundaries ({111} twins), with many growths showing no other boundaries. These twins mediate the growth of the crystal, as they serve as the points for heterogeneous surface nucleation of adatom clusters. The twins can form after the crystal nucleates and are strongly preferred in order to obtain appreciable crystal growth rates. We model the growths from the confining channels in order to find the optimum channel geometry for large, uniform, single-crystal growths that consistently emerge from the channel. The growths from 2D confinement show lower trap density than those from 1 D confinement, indicating a further enhancement of the crystal quality due to the increased confinement. This method of single-crystal growth from an amorphous substrate is extensible to any materials system in which selective non-epitaxial deposition is possible.
by Kevin A. McComber.
Ph.D.
Huang, Ting-Yun Sasha. "Stability of nanostructured : amorphous aluminum-manganese alloys." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104107.
Full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 113-122).
Nanocrystalline alloys have attracted interest for decades because of their improved mechanical strength without sacrificing ductility, but structural stability has always been an issue. In this work, bulk aluminum-manganese (Al-Mn) nanocrystalline alloys have been synthesized using room temperature ionic liquid electrodeposition, by which various nanostructures and dual-phase structures can be created by controlling the Mn solute incorporation level. The manganese exhibits grain boundary segregation in the Al-Mn solid solution in the as-deposited condition, which contributes to enhanced stability of the nanostructure. The grain boundary properties of the nanostructured alloys were studied via three dimensional atom probe tomography and aberration-corrected scanning electron microscopy. The segregation energies were calculated based on the experimental results and compared with the values calculated from a thermodynamic-based segregation model. Upon heating of the nanostructured and dual-phase alloys, a variety of complex phase transformations occur. A combination of X-ray diffraction, transmission electron microscopy, as well as differential scanning calorimetry were employed to understand the phase transformation mechanisms and grain growth processes. A Johnson-Mehl-Avrami-Kolmogorov analytical model was proposed as a descriptive method to explain the phase transformation sequence. Using the parameters extracted from the analytical model, predictive time-temperature transformation diagrams were constructed. The stability region of the alloy in time-temperature space is thus established, providing a simple way to evaluate nanostructure stability.
by Ting-Yun Sasha Huang.
Ph. D.
Zhan, Xun. "Crystallization Micro-mechanism of Amorphous Ni-P." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1489757814121594.
Full textRabias, J. "Power loss in amorphous ribbon materials : The effect of surface roughness on the power loss and harmonic content of flux density of amorphous ribbon materials." Thesis, Bucks New University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375618.
Full textJenket, Donald R. (Donald Robert). "Electrodeposition of amorphous matrix Ni-W/Wp̳ composites." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32847.
Full textIn title on t.p., double-underscored "p" appears as subscript.
Includes bibliographical references (p. 17).
An amorphous Ni-W alloy matrix was incorporated with W particulate through two types of electrodeposition. The plating bath for the electrodeposition contained nickel sulfate, sodium tungstate, sodium citrate, ammonium chloride, and a variable amount of 1 gm tungsten particulate ranging in concentration from about 5g/L to 15g/L.The first method was electrodeposition with only moderate stirring of the plating bath. The second method had a forced flow of solution on the substrate via a pump. The results showed incorporation in both methods, but the flowed method resulted in more incorporation. The amount of incorporation increased with the amount of particulate in solution until a limit that lies somewhere between 10g/L and 15g/L of particle concentration. At this point, the incorporation became hindered by the excess amount of particulate in solution. It was also shown that an increase of particulate concentration caused more voids in the material, and the flowed method caused less voids than the normal method. A tapering in the amount of incorporation between the substrate side and the surface side of the deposit was observed; the area close to the substrate had a higher incorporation than the area near the surface. Hardness testing showed mechanical property differences through the thickness of the deposit with the area near the substrate being softer than the area near the surface. Compression testing showed an increase in the strain and a decrease in the stress before failure, suggesting an improvement in ductility.
by Donald R. Jenket, II.
S.B.
Muralidharan, Krishna. "Molecular dynamics simulations of brittle fracture in amorphous silica." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280634.
Full textLuckas, Jennifer Maria [Verfasser]. "Electronic transport in amorphous phase-change materials / Jennifer Maria Luckas." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2013. http://d-nb.info/1033024333/34.
Full textWetherall, Kate M. "The Structure of Amorphous Calcium Phosphate and othe phosphate materials." Thesis, University of Kent, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520863.
Full textAkdaş, Deniz Güneş Mehmet. "Sub-Gap absorption spectroscopy and its applications to amorphous semiconductor materials/." [s.l.]: [s.n.], 2002. http://library.iyte.edu.tr/tezler/master/malzemebilimivemuh/T000127.pdf.
Full textBaumer, Richard E. (Richard Edward). "Atomistic simulations of radiation damage in amorphous metal alloys." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/88363.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (pages 121-131).
While numerous fundamental studies have characterized the atomic-level radiation response mechanisms in irradiated crystalline alloys, comparatively little is known regarding the mechanisms of radiation damage in amorphous alloys. Knowledge of collision cascade dynamics is lacking, both with respect to the possibility of sub-cascade formation and concerning the types of damage created in individual cascades. This Thesis resolves these knowledge gaps through a systematic simulation study of the radiation response of amorphous metal alloys. Using a molecular dynamics simulation of /2 MeV ion irradiation in a realistic 2 billion-atom molecular dynamics simulation in amorphous Cu₅₀Nb₅₀, I show that radiation creates isolated nanometer-scale zones with rapidly quenching liquids. Quenched liquids reach large pressures and emit stress pulses that trigger polarized plastic deformation in adjacent material. In order to identify liquid zones in irradiated amorphous Cu₅₀Nb₅₀, I use molecular dynamics simulations to characterize the properties and glass transition temperature of uniform liquid Cu-Nb alloys. I show that radiation-induced liquid zones rapidly quench to material with the same properties as a uniform liquid quenched at an equivalent quench rate approaching 1014 K/s. These "super-quenched zones" (SQZs) are approximately 10 nm in diameter and provide a mechanistic explanation for radiation-induced swelling and ductilization in metallic glasses. The identification of plasticity adjacent to SQZs is an unexpected damage mechanism that could prove a limiting factor for the application of amorphous alloys in radiation environments. To aid selection of amorphous alloys with resistance to collision-induced plasticity, I formulate a micro-mechanical model for collision-induced plasticity in irradiated metallic glasses. The analytical model successfully ranks the damage-resistance of irradiated Cu- Nb alloys and should enable selection of amorphous alloys with optimized radiation tolerance. Finally, through characterization of quenched Cu₅₀Nb₅₀, I reveal that glass transition in Cu₅₀Nb₅₀ occurs by gelation due to formation of a mechanically stiff, percolating network of atoms with icosahedral local packing at the interfaces between compositionally enriched regions. These features of glass transition are similar to gelation processes in polymeric and colloidal gels and suggest new approaches for understanding glass transition in bulk metallic glasses.
by Richard E. Baumer.
Ph. D.
Merazga, Amar. "Steady state and transient photoconductivity in n-type amorphous silicon." Thesis, University of Abertay Dundee, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277887.
Full textAhlström, Olle. "Characterizing the state of water in an amorphous magnesium carbonate using Dielectric spectroscopy." Thesis, Uppsala universitet, Nanoteknologi och funktionella material, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-200931.
Full textChattoraj, Joyjit. "Effect of finite temperatures on the elementary mechanisms of plastic deformation in amorphous materials." Thesis, Paris Est, 2011. http://www.theses.fr/2011PEST1074/document.
Full textUsing numerical simulations of a model two-dimensional Lennard-Jones glass, we study the effect of small temperatures on the elementary mechanisms of deformation in amorphous materials. A very extensive data set covering several decades of shear rate at various temperatures below and up to the glass transition was compiled. Measurements, which include transverse diffusion, macroscopic stress, and coarse-grained fields (strain, stress) and their spatial correlations, lead us to propose that the avalanche dynamics previously identified in athermal simulations continues to be at work -- and nearly unchanged -- up to the glass transition. It is then argued that in this range, thermal fluctuation essentially shift the strains at which dissipative events take place, which results in a sharp drop of the macroscopic stress level at the lowest temperatures
Mohammed, K. A. "Low temperature specific heat measurements of crystalline and amorphous magnetic materials." Thesis, University of Southampton, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356096.
Full textFong, Hon Hang. "Transport and luminance of organic electronic materials." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/612.
Full textRaanaei, Hossein. "Tailoring Properties of Materials at the Nanoscale." Doctoral thesis, Uppsala : Uppsala University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-107425.
Full textMaheswaram, Manik Pavan Kumar. "Characterization of Pharmaceutical Materials by Thermal and Analytical Methods." Cleveland State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=csu1358131244.
Full textWolford, Ian Mark. "Quantifying Amorphous Content of Commercially Available Silicon Carbide Fibers." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1472054006.
Full textPrasai, Kiran. "Gap Engineering and Simulation of Advanced Materials." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1503393620371266.
Full text