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 90 for “"ferroelectrics"”.
-
Dielectric noise spectroscopy of relaxor ferroelectrics
… one simple question: are the dynamics of relaxor ferroelectrics cooperative? To accomplish this task, we have developed a promising new technique that is excellent at sorting out the internal dynamics of high dielectric materials. Specifically we have examined the dynamics of the relaxor …
-
Structure-property correlations in compositionally complex ferroelectrics
… to the emergence of unconventional behavior. Ferroelectrics with switchable polar ordering, for instance, are influenced by local compositional variation, thus requiring an understanding of structure-property relationships. My dissertation work focuses on using atomic scale characterization …
-
Local-scale optical properties of single-crystal ferroelectrics
Das Ziel dieser Arbeit ist die optische Untersuchung von ferroelektrischen Domänen und Domänenwänden auf lokaler Skala. Dafür wurden neuartige nichtinvasive Ansätze entwickelt, die auf der Anwendung optischer Rastersondenmikroskopie basieren. Die untersuchten Schlüsseleigenschaften umfassen den …
-
Microstructural dynamics induced by nanoscale stress in ferroelectrics
… aspect of harnessing the functionality of ferroelectrics for such devices involves locally controlling and understanding the microstructural dynamics such as ferroelectric switching behaviour and domain wall motion. Intuitively, electric fields have been extensively used to probe and …
-
Transmission Electron Microscopy Study of Domains in Ferroelectrics
This thesis investigates domain dynamics in one of the most well-known ferroelectric materials – polycrystalline BaTiO<sub>3</sub> ceramics, and one of today’s most promising ferroelectric materials for future device applications – mixed-phase BiFeO<sub>3</sub> thin films. The investigations use …
-
A Micromechanics Study on Ferroelectrics and Multiferroic Composites
… results. First, we focus on the investigation of ferroelectrics and its composites. Based on the experimental observations, the nonlinear electromechanical coupling responses of ferroelectrics are strongly depending on the frequency of the applied electric field. In order to interpret the …
-
Aging and Barkhausen noise in the relaxor ferroelectrics
"Relaxor ferroelectrics are disordered crystalline materials whose polar order is limited to mesoscopic-scaled nanodomains. There is no ferroelectric phase transition, but a faster than Arrhenius cooperative freezing into a glassy relaxor regime instead. It is not understood how the random fields …
-
Structure-property relationships in strontium barium niobate relaxor ferroelectrics
Studies of the structure-property relationships in strontium barium niobate Sr$\sb{\rm x}\rm Ba\sb{1-x}Nb\sb2O\sb6$ (SBN x/1 $-$ x) have been performed using a combination of dielectric spectroscopy, Sawyer-Tower polarization techniques, and transmission electron microscopy (TEM). The dielectric …
-
Electrical transport and superconductivity in doped quantum critical ferroelectrics
… and superconductivity in doped quantum critical ferroelectrics) presents the results of research into the electrical transport and superconductivity found in the neighbourhood of quantum phase transitions in carrier-doped ferroelectrics and paraelectrics. The materials of interest are doped …
-
Computer Modeling and Simulation of Morphotropic Phase Boundary Ferroelectrics
… crystals and polycrystals of perovskite-type ferroelectrics around the morphotropic phase boundary (MPB). The findings include: (I) Coherent phase decomposition near MPB in PZT is investigated. It reveals characteristic multidomain microstructures, where nanoscale lamellar domains of …
-
Domain patterns and domain wall dynamics in small-scale ferroelectrics
… dynamics of switching in meso/nanoscale ferroelectrics incorporated into device geometries, and secondly, the development of control over the precise mechanics of switching by altering the ferroelectric morphology therein.<br/><br/> In addressing the first theme, thin single-crystal …
-
Vertically-aligned Oxide Nanocomposite Films for Improved Ferroelectrics and Ferromagnetics
In this work, I start by introducing a relatively recently innovated thin film architecture which offers a new direction in strain control, the vertically aligned nanocomposite (VAN). I first present the literature in the field, explaining the advantages and unique novel properties stemming from …
-
Non-volatile reconfigurable transistors enabled by ferroelectrics for logic-in-memory applications
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2023-12-04 without embargo terms
-
Development of phonon-polarization THz spectroscopy, and the investigation of relaxor ferroelectrics
This thesis develops phonon-polariton based THz spectroscopy and uses this technique to make the first THz frequency dielectric measurements of a relaxor ferroelectric crystal, in particular KTao0.982Nb0.018O3 (KTN 1.8). THz spectroscopy has emerged as an important probe for a wide variety of …
-
Probing Nanoscale Functional Properties of Perovskite and Wurtzite Ferroelectrics via Scanning Probe Microscopy
… applications in science and technology. Ferroelectrics exhibit a switchable spontaneous polarization when subjected to an electric field and are instrumental in developing low-energy nanoelectronics. Topologically tailored nanoscale ferroelectrics have attracted substantial attention in …
-
Investigation of polarization switching over broad time and field domains in various ferroelectrics
… domains, in various modified Pb-based perovskite ferroelectrics, were systematically performed by ferroelectric switching current transient and bipolar drive P-E responses. Studies were performed from E«Ec to E»Ec, where Ec is the coercive field These investigations have shown the presence of …
-
Three-dimensional polarization probing in polymer ferroelectrics, polymer-dispersed liquid crystals, and polymer ferroelectrets
A key non-destructive technique for analysis, optimization and developing of new functional materials such as sensors, transducers, electro-optical and memory devices is presented. The Thermal-Pulse Tomography (TPT) provides high-resolution three-dimensional images of electric field and …
-
Static and Dynamical Properties of Ferroelectrics and Related Material in Bulk and Nanostructure Forms
<p>Ferroelectrics (FE) and multiferroics (MFE) have attracted a lot of attentions due to their rich and novel properties. Studies towards FE and MFE are of both fundamental and technological importance. We use a first-principles-based effective Hamiltonian method, conventional ab-initio packages and …
-
Synchrotron X -Ray Scattering Studies of Local Fluctuations in Lead Magnesium Niobate Relaxor Ferroelectrics
Temperature dependent synchrotron x-ray diffraction studies of PMN-PT single crystals confirmed the existence of anti-ferroelectric fluctuations produced by correlated atomic displacements using state-of-the art experimental facilities. Detailed quantitative analysis of the corresponding …
Page 1 of 5