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.
Results
Showing 1 to 20 of 42 for “"Vibrational Properties"”.
-
Electronic and lattice vibrational properties of thorium hydrides
… these compounds are bulk superconductors whose properties do not deviate appreciably from the predictions of the BCS theory. Both the normalized specific heat discontinuity at Tc and the ratio of the energy gap to Tc are comparable to those of other weak-coupled superconductors. A re1ative1y …
-
Diagrammatic many-body methods for anharmonic molecular vibrational properties
… methods for computing the energies and other properties of anharmonic vibrations have been developed based on the Dyson equation formalism for the single-particle vibrational Green's function and the many-body perturbation theory for the total zero-point energy. Unlike similar methods based on …
-
Optical anisotropy and vibrational properties of Sn, In, and Cs nanowires
In der vorliegenden Arbeit wurden die optischen Eigenschaften von Quantendrähten aus den Metallen Sn, In und Cs mit Hilfe der Reflexions Anisotropie Spektroskopie (RAS), sowie zusätzlich deren Schwingungsmoden mit der Ramanspektroskopie untersucht. Die durch selbstorganisiertes Wachstum des …
-
The Effects of Strain and Vacancies on the Electric and Vibrational Properties of Ferroelectric BaTiO3 from First-principles
… because of the multitude of applicable properties that ferroelectric materials exhibit. The mastery, and control of these properties necessitate the knowledge of the fundamental physics governing these insulating materials.</p> <p>In this dissertation I present the results of …
-
Raman spectroscopy of single wall carbon nanotubes
… ratio, a SWNT has very unique electronic and vibrational properties. The goals of this thesis work are to design and construct a Raman instrument capable of obtaining signals from many different types of individual SWNTs, to develop methods and tools to collect, organize and analyze large …
-
I. Raman scattering and x-ray diffraction study of annealing effects on confined LO and folded LA phonons in gallium arsenide-aluminum arsenide superlattices. II. Picosecond light scattering studies of relaxation and tunneling in gallium arsenide/aluminum(x)gallium(1-x)arsenide multiple quantum well structures
… used light scattering techniques to probe the vibrational properties of GaAs/AlAs superlattices and the dynamics of electrons in GaAs/Al$\sb{\rm x}$Ga$\sb{\rm 1-x}$As multiple quantum well structures.
-
Vibrational dynamics in strong glasses: the cases of densified v-SiO2 and v-SiSe2
In this work we will face the problem of the vibrational properties of glasses focusing on the origin and nature of the boson peak (BP). This feature is an universal characteristic of glasses and a fingerprint of the presence of disorder. Two samples have been chosen for this study. The first is …
-
Effects of Ultrathin Interlayers on Thermal Boundary Conductance at Metal-Dielectric Interfaces
… depends on an interplay between the phonon vibrational properties and metal electron-phonon coupling strength overlap.
-
Electron spin-lattice relaxation in two heme iron and two blue-copper proteins at liquid helium temperatures
… form consistent with a crossover in the vibrational properties is proposed instead, similar to the localization crossover in amorphous materials.
-
Photophysics of carbon nanotubes
… carbon nanotubes. Studying the electronic and vibrational properties of carbon nanotubes, we find that carbon nanotubes less than 1 nm in diameter exhibit dramatic changes in their electron and phonon dispersion relations due to the curvature of the nanotube sidewall and the enhanced electron …
-
Hard, Soft, and Sticky Spheres for Dynamical Studies of Disordered Colloidal Packings
… as a means to alter, and control, the properties of dense colloidal packings. The first set of experiments studied phonon modes in two-dimensional colloidal crystals composed of soft microgel particles with hard polystyrene particle dopants distributed randomly on the triangular …
-
Coffee-Rings and Glasses: Colloids Out of Equilibrium
… study of the effects of particle shape on the vibrational properties of colloidal glasses. Low frequency modes in glasses composed of slightly anisotropic particles are found to have predominantly rotational character. Conversely, low frequency modes in glasses of highly anisotropic particles …
-
Emergent properties of misfit layer compounds from first principles.
… making the design of misfits’ emergent properties hindered by a lack of a global picture. Our work offers an original perspective by deriving misfits’ properties from those of their constituent layers. We identify the fundamental mechanism governing charge transfer and demonstrate how …
-
First-principles transition-metal catalysis : efficient and accurate approaches for studying enzymatic systems
… systems: spin state splittings and structural properties of Fe2 and other small molecules as well as the addition-elimination reactions of hydrogen and methane on FeO+ to form water and methanol, respectively. We find that errors from common density functionals which are over 1.0 eV are greatly …
-
Ab initio calculations of phonon properties and spectra in condensed matter
… are important in studying many solid state properties, ranging from Raman, infrared, and neutron scattering to thermal expansion, specific heat, and heat conductivity to electrical resistivity and superconductivity. Generally, modeling the interatomic forces and vibrational modes of a given …
-
Topics in semiconductor physics: Part I. Phonons in semiconducting alloys and alloy superlattices ; Part II. Deep energy levels of defects in mercury cadmium telluride and wurtzite semiconductors
… parts. The first part is devoted to the study of vibrational properties of semiconducting alloys and alloy superlattices. The second part deals with deep energy levels of defects in semiconductors. In Part I, densities of phonon states are evaluated using the recursion method for quasi-binary …
-
Evaluations of single walled carbon nanotubes using resonance Raman spectroscopy
… use resonance Raman scattering to evaluate the vibrational properties of single walled carbon nanotubes (SWNTs). In the first study, we report an evaluation of second-order combination and over-tone modes in highly ordered pyrolytic graphite (HOPG), in SWNT bundles, and in isolated SWNTs. We …
-
Optical Properties of Rare-Earth Doped YBO3 Phosphor Materials
… diodes (WLEDs). YBO3:Eu3+ offers exceptional properties such as high optical damage threshold, high quantum efficiency in deep ultraviolet region (UV) but this material has a chromaticity problem due to its orange (591 nm, O) and red (611 & 627 nm, R) emission. The red color along with high …
-
Remaining Unperturbed by the Vibrational Response: Probing Vibrational Coupling, Relaxation, and Solvent Effects with 2D IR Spectroscopy
… laser technique that is capable of probing the vibrational properties and dynamics down to the picosecond or even femtosecond timescales. This technique enables the analysis of vibrational couplings, energy redistribution pathways, and solvation dynamics in real time. The early chapters of this …
-
Atomic Modelling of Disorder in Metal Nanocrystals
… science studies to calculate measurable properties from the atomic trajectories of simulations; for example, the diffusion coefficient, which according to Einstein relations (Einstein 1905) on the random walk is 1/6 of the slope of the trend of  ̄(σ_i^2 ) vs. time (Chandler 1987). …
Page 1 of 3