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 20 for “"epitaxial thin films"”.
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X-ray scattering studies of strongly correlated materials: orbital ordering in KCuF3 and stripe-like domain structures in BiFeO3 epitaxial thin films
… arrays of stripe-like ferroelectric domains in epitaxial thin films of multiferroic BiFeO3 are presented in this dissertation. Both resonant soft x-ray elastic scattering and non-resonant hard x-ray elastic scattering probes were used. Our experiments on KCuF3 have revealed a previously …
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Epitaxial growth of semiconductors and chiral metal surfaces using spin coating and electrodeposition
"The current primary methods for epitaxial growth are energy intensive, requiring high temperature or high vacuum to obtain quality thin films. This dissertation explores the solution process methods of electrodeposition and spin coating for growth of epitaxial thin films. First, a method is …
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Structural, Magnetic, Dielectric, and Optical Properties of DyCrO3 and GeNi2O4 Materials
… transition at a higher temperature. Thin films of these compounds are widely researched for their applications in spintronics. The investigation of the structural, magnetic, dielectric, and optical properties of deposited thin films of these two materials can contribute to a better …
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Growth of epitaxial nanoscale columnar copper indium diselinide thin films by introduction of sodium flouride during growth
The effect of NaF on the growth of CuInSe2 (CIS) epitaxial thin films by a hybrid sputtering and evaporation method was studied. Low levels of NaF deposition during interruptions of epitaxial growth reduced surface roughness. Larger amounts of NaF resulted in columnar epitaxial films with <112> …
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Structure-Property Relations on Strain-Mediated Multiferroic Heterostructures
Multiferroic thin-film heterostructures have attracted a great deal of attention due to the increasing demand for novel energy-efficient micro/nano-electronic devices. Both single phase multiferroic materials like BiFeO3 (BFO) thin films, and strain-mediated magnetoelectric (ME) nanocomposites, …
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Besetzte und unbesetzte elektronische Struktur von geordneten Dünnschichtverbindungen der Seltenen Erden Eu und Yb mit den Übergangsmetallen Pd und Ni
… and Ni. The compounds were prepared in-situ as epitaxial thin films on single-crystalline substrates. For comparison, the experiments were extended to a Ba/Pd compound, which was prepared in the same way. All samples were characterised by low-energy electron diffraction (LEED), photoelectron …
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Investigation of Ferroelectric Thin Film Using Piezoresponse Force Microscopy
… tetragonal polycrystalline PbZr0.3Ti0.7O3 and epitaxial PbZr0.2Ti0.8O3 thin films were studied at different length scales using resonant PFM. This technique was also used to study the ferroelectric/ferroelastic domains and their dynamics. In the current work, the interplay between ferroelectric …
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Understanding the catalytic activity of oxides through their electronic structure and surface chemistry
… catalyst systems. Electrochemical studies of epitaxial oxide thin films establish the intrinsic activity of oxide catalysts in a way that cannot be realized with polydisperse nanoparticle systems. This thesis has isolated the activity of the catalyst on a true surface-area basis, enabling an …
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Induced Phase Transition in Magnetoelectric BiFeO3 Crystals, Thin-layers and Ceramics
… also investigated phase induced transition by epitaxial constraint, and substituent and cystalline solution effects. Variously oriented BiFeO₃ epitaxial thin films have been deposited by pulsed laser deposition. Dramatically enhanced polarization has been found for (001)c, (110)c, and (111)c …
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Diluted Magnetic Semiconductor Cobalt and Europium Implanted ZnO Thin Film
… of cobalt and europium into ZnO/c-Al2O3 (0001) epitaxial thin films. The ion implantation is an effective technique for introducing dopants of heavy elements into thin film. The depth profile of as-prepared sample as well as dopants concentration was studied by ion beam analysis and transport of …
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Magnetoelectric Oxide Nanocomposite Heterostructures
… (ME) effect. Recently, with the development of thin film growth techniques, the multiferroics magnetoelectric composite heterostructures exhibit a very promising future prospects. This dissertation focused on the design, fabrication and characterization of new multiferroics magnetoelectric …
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Magnetoelectric Properties of Epitaxial Spinel Oxide Thin Films
… functional characterization of high-quality FVO epitaxial thin films on perovskite SrTiO3 substrates. The magnetic and electrical properties of FVO films are presented as well as the characterization of magnetoelectric coupling of the material. Secondly, another unique spinel, Cobalt Chromite, …
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Growth and Characterization of Epitaxial Oxide Thin Films
Epitaxial oxide thin films are used in many technologically important device applications. This work deals with the deposition and characterization of epitaxial WO3 and SrBi2Ta2O9 (SBT) thin films on single crystal oxide substrates. WO3 thin films were chosen as a subject of study because of recent …
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Metallorganische Chemische Gasphasenabscheidung (MOCVD) ferroelektrischer Dünnschichten : Herstellung und Charakterisierung
… memory using ferroelectric crystalline thin films (FeRAM) are a possible replacement for Flash- and DRAM-memory with equivalent or superior performance. Ferroelectric films consisting of lead zirconate titanate (PZT) are a promising candidate for the application in these memory devices. …
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Advanced Synthesis of Ultra-High Temperature Ceramics (UHTCs) and High Temperature Electron Emitting Materials
… densified via UHS to >90% relative density within 60 second in vacuum without pressure. The effect of sintering time on densification and final grain size were studied. An innovative process for manufacturing bulk UHTC materials was studied and is detailed herein. Second, the work function …
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Microstructure and Texture of Yttrium-Nickel-Borocarbide and Samarium-Cobalt Thin Films
… Yttrium-Nickel- Borocarbide and Samarium-Cobalt thin film heterostructures prepared by Pulsed Laser Deposition and to establish structure-property relations for these materials in order to improve their properties and design new structures. Coincidence site lattice epitaxy was explored in most of …
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Heat transport by phonons in crystalline materials and nanostructures
… to the reduction in the thermal conductivity of epitaxial thin films, indicating that frequency dependence and thickness dependence of thermal conductivity are fundamentally equivalent. I developed the frequency dependence of thermal conductivity into a convenient probe of phonon mean-free-paths, …
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New modalities of strain-based engineering of ferroelectrics: domain structure and properties of PbZr1-xTixO3 thin films
Epitaxial strain has been widely used to modify the crystal and domain structure, and ultimately the dielectric, ferroelectric, and pyroelectric responses of ferroelectric thin-films for a wide variety of applications including memories, transducers, energy harvesters, sensors, and many more. …
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Orientation dependence of dielectric susceptibilities and switching characteristics in epitaxial ferroelectric thin films
… the intrinsic response of the polarization within a domain and so-called extrinsic contributions from the motion of domain walls have been studied, the non-motional or stationary contribution from the material within the finite width of the domain wall itself has been particularly difficult to …
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Geometric frustration in high spin orbit coupling magnetic materials
… inelastic scattering measurements on powders and epitaxial thin films. In both samples we observe a phase transition at $T = 90$~K. In the bulk sample a weak ($\frac{\Delta a}{a} \sim 10^{-4}$), first order structural phase transition at $T^* = 90$~K is found. This transition is characterized by a …