Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 23 for “"density function theory"”.
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Synthesis and growth dynamics study of silver nanoparticles
… work are outlined. Chapter two deals with the theory of kinetically growth of nanoparticles. The basic optical properties of metal nanoparticles as well as the structural evolution of nanoparticles are also mentioned in this chapter In Chapter three the synthesis of silver nanoparticles with …
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Synthesis and Assembly of Dihydroindolizines on Gold Surfaces for Light Induced Work Function Alterations
… is demonstrated to alter the work function of the underlying substrate (170 meV). This same molecule also provides spectroscopic signatures for correlating the change in molecular structure to the induced change in the surfaces' electronic properties. Polarization modulation …
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Emerging phenomena in oxide heterostructures
… interact with each other. In particular, density function theory (DFT) has provided significant insight into underlying physics of materials at the atomic level, giving quantitative results consistent with experiment. In this dissertation using density functional theory methods, we explore …
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Nonadiabatic Dynamics of Cis-Trans Photoisomerization --- a First Principles Study
… method can simulate the full time-dependent wavefunction of molecules with tens of atoms. AIMS data can be directly compared to the results of ultrafast time-resolved photoelectron spectroscopy data. This allows both the reinterpretation of the experiment and the validation of the simulations. …
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A study on the properties of graphene nanoribbons for electronics
Graphene has the potential to lead the construction of next-generation electronics due to its high mobility, high thermal conductivity, and atomically thin two-dimensional structure. However, graphene’s intrinsic zero bandgap property restricts its use in a wide range of applications. Thus, the …
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Inkjet printing multifunctional chromatic sensors and chromism study
… side chain effect on the sensitivity of PDA, Density Function Theory (DFT) simulation is conducted, and the results show that the torsion of C-C bond is closely related to the length of the alkyl side chain.
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Transient Optical Picocavities Within Coupled Plasmonic Nanostructures
… by comparing experimental data to a theoretical Density Function Theory model. Next, I extract the spatial distribution of picocavity formation in the gap by comparing transient scattering at two simultaneous wavelengths of light. Picocavities are found to more likely form at regions of higher …
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Oxygen diffusion through titanium and other HCP metals
… alloys, due to their high tensile strength, low density, and excellent corrosion resistance, have great potential in aerospace and medical implant applications. However, Ti alloy properties are very sensitive to oxygen content and readily oxidizes at high temperatures. Ab initio density …
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Characterizations on bacterial photosynthesis and respiration with optical spectroscopy and magnetic resonance
… being anionic. Molecular dynamics and density function theory calculations have also being carried out to provide a realistic model of semiquinone in bo3 oxidase.
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Atomistic and finite element modeling of zirconia for thermal barrier coating applications
… including lattice parameter, band structure, density of state, as well as elastic constants for both monoclinic and tetragonal zirconia have been computed. The pressure-dependent phase transition between tetragonal (t-ZrO2) and cubic zirconia (c-ZrO2) has been calculated using the density …
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Design and fabrication of non-noble-metal electrocatalysts for oxygen reduction reactions.
… including high efficiency, high energy density and zero waste emission. However, a current fuel cell requires noble-metal catalysts (in most cased platinum, Pt) to accelerate the electrode reactions. As a result of the high cost of Pt, the commercialization of fuel cell has been severely …
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Studying phonon mean free paths at the nanoscale : modeling and experiments
… is termed thermal conductivity accumulation function. In this thesis, we advance a thermal conductivity spectroscopy technique based upon experimental observation of non-diffusive thermal transport using wire grid linear polarizer in conjunction with time-domain thermoreflectance (TDTR) …
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Fischer and N-heterocyclic carbene complexes of Group (VII) transition metals
… transition metals were investigated. By using density function theory calculations, the structural and electronic parameters could be elucidated and the fundamental bonding interactions between the carbene ligands and transition metals defined. The bonding definition provided a platform for the …
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Elucidating the structures of ionic clusters, from ion-water complexes to ion-biomolecule-water complexes
… cations (Li+ and Na+), with higher charge density, prefer to form structural configurations with extended linear networks of hydrogen bonds. Larger cations (Rb+ and Cs+), with lower charge density, prefer to generate configurations with cyclic hydrogen-bonded water subunits. It appears that …
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Influence of lattice dynamics on the ionic conductivity and stability of solid-state lithium-ion conductors
… inelastic neutron scattering measurements with density function theory computation, greater lithium ion mobility was correlated with decreasing lithium vibration frequency that was quantified using a newly proposed descriptor which we phonon band centers. Known superionic lithium conductors were …
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Structure and activity relationships of bimetallic catalysts for aqueous phase reforming and the water-gas shift reaction
… water dissociation barriers were estimated by density function theory (DFT) calculations of OH binding energies on Pt<sub>3</sub>M (111) surfaces. A volcano plot of WGS and APR reaction rates with OH binding energy was obtained. Additionally, DFT revealed that the more oxophillic metal …
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Optimization of Materials for Magnetic Refrigeration and Thermomagnetic Power Generation
… are considered: (i) hard ferrite magnets as the functional material for a two-quadrant TMG cycle; (ii) and a hard magnet applying a bias eld to a soft functional material, thus opening the second quadrant of the M-H plane. Experiments on commercially available hard ferrites reveal that these …
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All Inorganic Colloidal Perovskite Nanocrystals for Optoelectronic Applications
… measurements. These results, together with density function theory calculations, suggest that the defect tolerance found in band-edge charge-carriers can be extended to hot carriers. That is, the relaxation kinetics of hot carriers in materials with shallower defect states, such as I-based …
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Quantum Monte Carlo simulations of electrons and holes
… and a hole, and obey Bose statistics. A low density exciton gas is an experimentally realizable dilute Bose gas. The scattering length a8 of a dilute Bose gas determines its properties, but is difficult to calculate. We present an essentially exact QMC treatment of exciton-exciton scattering, …
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Designing Two-Dimensional Nanomaterials for Electrocatalytic Clean Energy Conversion
… discussed based on different compositions and functions followed by specific design principles. Following this, various 2D electrocatalysts for a series of electrocatalytic processes involved in the water cycle, carbon cycle, and nitrogen cycle are discussed from their fundamental conception to …
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