Sökning: "Electronic phase transitions"

Visar resultat 1 - 5 av 57 avhandlingar innehållade orden Electronic phase transitions.

1. 1. Electronic transitions and correlation effects : From pure elements to complex materials

   Författare :Johan Jönsson; Igor A. Abrikosov; Marcus Ekholm; Sergei Dudarev; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electronic transition; solid state physics; condensed matter physics; correlation effects;

   Sammanfattning : Macroscopic properties of real materials, such as conductivity, magneticproperties, crystal structure parameters, etc. are closely related or evendetermined by the configuration of their electrons, characterized by electronicstructure. By changing the conditions, e.g, pressure, temperature, magnetic/electric field, chemical doping, etc. LÄS MER

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

   Författare :Thanayut Kaewmaraya; Rajeev Ahuja; Scheicher Ralph; Naurang Saini; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 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;

   Sammanfattning : 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. LÄS MER

4. 3. Nanocalorimetry of electronic phase transitions in systems with unconventional superconductivity and magnetic ordering

   Författare :Donato Campanini; Andreas Rydh; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanocalorimetry; Superconductivity; Magnetism; Electronic phase transitions; Physics Of Matter; materiefysik; fysik; Physics;

   Sammanfattning : In this thesis, low temperature specific heat measurements on small (μg) single crystals of different superconducting and magnetic systems are presented. The device used in this work features a combination of high sensitivity and good accuracy over the temperature range 1-400 K and allows measurements in high magnetic fields. LÄS MER

5. 4. Understanding Physical Reality via Virtual Experiments

   Författare :Sergiu Arapan; Rajeev Ahuja; Börje Johansson; Chris Pickard; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density functional theory; ab initio calculations; electronic structure; lattice dynamics; high-pressure phase transitions; high-temperature phase transitions; incommensurate structures; Condensed matter physics; Kondenserade materiens fysik;

   Sammanfattning : In this thesis I have studied some problems of condensed matter at high pressures and temperatures by means of numerical simulations based on Density Functional Theory (DFT).The stability of MgCO3 and CaCO3 carbonates at the Earth's mantle conditions may play an important role in the global carbon cycle through the subduction of the oceanic crust. LÄS MER

7. 5. Designing and Tuning the Properties of Materials by Quantum Mechanical Calculations

   Författare :Jailton Souza de Almeida; Rajeev Ahuja; Patrizia Monachesi; Uppsala universitet; []
   Nyckelord :Physics; Density Functional Theory; Electronic Structure; Phase Transitions; High Pressure; Optical Properties; Dielectric Functions; Semiconductors; Metals; Fysik;

   Sammanfattning : In many materials, changes in chemical composition, pressure or temperature can induce metal to insulator transitions. It is recently observed in yttrium hydride, for example, changes from a shiny mirror (YH2) to a transparent window (YH3), which has important technological application in optical devices. LÄS MER