Sökning: "Ab initio lattice dynamics"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden Ab initio lattice dynamics.

  1. 1. Ab initio Lattice Dynamics Hydrogen-dense and Other Materials

    Detta är en avhandling från Uppsala : Universitetsbiblioteket

    Författare :Duck Young Kim; Uppsala universitet.; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Density functional theory; Density functional perturbation theory; Hydrogen-dense materials; Phase transition; High pressure; Ab initio lattice dynamics; Superconductivity; Quasi-particle approximation; NATURAL SCIENCES Physics; NATURVETENSKAP Fysik;

    Sammanfattning : This thesis presents a theoretical study of materials under high pressure using ab initio lattice dynamics based on density functional theory and density functional perturbation theory using both super-cell and linear response approach.Ab initio lattice dynamics using super-cell approach is applied to compare our theoretical predictions with experimental findings. LÄS MER

  2. 2. Electronic Structure and Lattice Dynamics of Elements and Compounds

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Petros Souvatzis; Uppsala universitet.; [2007]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atomic and molecular physics; electronic structure; lattice dynamics; first-principles theory; self-consistent lattice dynamical calculation; elasticity; super plasticity; electronic topological transition; equation of state; Atom- och molekylfysik;

    Sammanfattning : The elastic constants of Mg(1-x)AlxB2 have been calculated in the regime 0<x<0.25. The calculations show that the ratio, B/G, between the bulk- and the shear-modulus stays well below the empirical ductility limit, 1. LÄS MER

  3. 3. Atomistic Spin Dynamics, Theory and Applications

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Johan Hellsvik; Uppsala universitet.; [2010]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ab initio calculations; spin dynamics; magnetization; magnetic switching; diluted magnetic semiconductors; spin glasses; ferromagnetic relaxation; ferrimagnets; antiferromagnets; NATURAL SCIENCES Physics Condensed matter physics Magnetism; NATURVETENSKAP Fysik Kondenserade materiens fysik Magnetism; NATURAL SCIENCES Physics Condensed matter physics; NATURVETENSKAP Fysik Kondenserade materiens fysik; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : The topic of this Thesis is magnetization dynamics on atomic length scales. A computational scheme, Atomistic Spin Dynamics, based on density functional theory, the adiabatic approximation and the atomic moment approximation is presented. LÄS MER

  4. 4. Understanding Physical Reality via Virtual Experiments

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Sergiu Arapan; Uppsala universitet.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density functional theory; ab initio calculations; electronic structure; lattice dynamics; high-pressure phase transitions; high-temperature phase transitions; incommensurate structures; NATURAL SCIENCES Physics Condensed matter physics; NATURVETENSKAP Fysik 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

  5. 5. Materials Design from ab initio Calculations

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Sa Li; Uppsala universitet.; [2004]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; DFT; MAX; Optics; phase transition; phonon; EOS; Fysik; NATURAL SCIENCES Physics; NATURVETENSKAP Fysik;

    Sammanfattning : This thesis presents a theoretical study of bulk materials using ab initio methods based on the density functional theory (DFT).Crystallographic structural phase transformations and phase stability for 5f-dioxides, ABO3 perovskites, and ABO4 compounds have been extensively studied. LÄS MER