Search for dissertations about: "phase transitions"

Showing result 1 - 5 of 227 swedish dissertations containing the words phase transitions.

  1. 1. Time-resolved X-ray diffraction studies of phonons and phase transitions

    Author : Ola Synnergren; Atomfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Fysik; Physics; Phase transitions; X-ray diffraction; Phonons; X-ray diffraction; phonons; phase transitions;

    Abstract : This thesis summarizes work in which time-resolved X-ray diffraction has been used to probe crystalline materials, thereby revealing the dynamics of phonons and phase transitions. X-ray diffraction is the standard tool in investigations of structure on the atomic scale. READ MORE

  2. 2. Phase transitions in novel superfluids and systems with correlated disorder

    Author : Hannes Meier; Mats Wallin; Asle Sudbø; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; condensed matter physics; phase transitions; critical phenomena; spin models; quantum phase transitions; quantum fluids; superfluidity; superconductivity; disordered systems; Bose glass; dirty bosons; vortex pinning; statistical mechanics; Monte Carlo simulation; Wolff algorithm; classical worm algorithm; Wang-Landau algorithm; Physics; Fysik;

    Abstract : Condensed matter systems undergoing phase transitions rarely allow exact solutions. The presence of disorder renders the situation  even worse but collective Monte Carlo methods and parallel algorithms allow numerical descriptions. READ MORE

  3. 3. Phase transitions in high-temperature superconductors

    Author : Jack Lidmar; KTH; []
    Keywords : Superconductivity; Vortices; Phase transitions; Strongly correlated fermions; High-temperature superconductivity; Monte Carlo simulations.; TECHNOLOGY; TEKNIKVETENSKAP;

    Abstract : Thermal fluctuations and disorder strongly influence the behaviour of hightemperature superconductors. In particular the vortices play a key role in determining their properties. In this thesis the main focus lies on phase transitions, both in ultra-thin films and in three-dimensional systems, which are driven by vortex fluctuations. READ MORE

  4. 4. First-Principles Studies of Materials Properties : Pressure-Induced Phase Transitions & Functional Materials

    Author : Thanayut Kaewmaraya; Rajeev Ahuja; Scheicher Ralph; Naurang Saini; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; Density functional theory; Pressure-induced phase transitions; Ab-initio molecular dynamic; hybrid functional; Ab-initio random structure searching; Phase change material; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : This thesis presents the first-principles studies of materials properties within the framework of the density functional theory (DFT). The thesis constitutes three main parts, i. e., pressure-induced phase transitions in solids, data-storage and clean-energy materials. READ MORE

  5. 5. Computer Simulations of Simple Liquids with Tetrahedral Local Order : the Supercooled Liquid, Solids and Phase Transitions

    Author : Måns Elenius; Mikhail Dzugutov; Jonathan Doye; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Simple liquids; glasses; liquid-glass transition; supercooled liquids; tetrahedral liquids; phase transitions; quasicrystals; molecular dynamics; Condensed matter physics; Kondenserade materiens fysik; Liquid physics; Vätskefysik; Numerical Analysis; numerisk analys;

    Abstract : The understanding of complex condensed matter systems is an area of intense study. In this thesis, some properties of simple liquids with strong preference for tetrahedral local ordering are explored. These liquids are amenable to supercooling, and give complex crystalline structures on eventual crystallisation. READ MORE