Search for dissertations about: "high-pressure phase transitions"

Showing result 1 - 5 of 26 swedish dissertations containing the words high-pressure phase transitions.

  2. 1. New Fullerene Materials Obtained in Solution and by High Pressure High Temperature Treatment

    Author : Alexandr Talyzin; B. Sundqvist; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry; fullerene; solution; high pressure; Raman spectroscopy; polymerisation; XRD; Kemi; Chemistry; Kemi; Inorganic Chemistry; oorganisk kemi;

    Abstract : Crystallization of C60 and C70 from organic solution often leads to the formation of new solvates and other fullerene compounds. In the present thesis, a number of such solvates were obtained and their phase transitions studied using in situ "in solution" techniques. READ MORE

  4. 2. Ultra high-pressure compaction of powder

    Author : Sven Berg; Javier Oliver; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Abstract : Sintering at high-pressure improves the properties of the material, either through new sintering aids becoming available or through improving intergranular bonding. This gives the manufactured products potential advantages like faster cut rates, and more precise and cleaner production methods that add up to cost efficiency and competitive edge. READ MORE

  5. 3. Density Functional Theory in Computational Materials Science

    Author : Jorge Mario Osorio Guillén; Rajeev Ahuja; Börje Johansson; Bruce N. Harmon; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Density Functional Theory; High Pressure; Phase Transitions; Elastic Properties; Lithium Batteries; Dilute Magnetic Semiconductors; Fysik; Physics; Fysik;

    Abstract : The present thesis is concerned to the application of first-principles self-consistent total-energy calculations within the density functional theory on different topics in materials science. Crystallographic phase-transitions under high-pressure has been study for TiO2, FeI2, Fe3O4, Ti, the heavy alkali metals Cs and Rb, and C3N4. READ MORE

  6. 4. Studies of carbon nanomaterials based on fullerenes and carbon nanotubes

    Author : Agnieszka Iwasiewicz-Wabnig; Bertil Sundqvist; Eleanor E.B. Campbell; Umeå universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fullerenes; carbon nanotubes; fullerene polymers; intercalation compounds; high pressure; Raman spectroscopy; X-ray diffraction; atomic force microscopy; phase transitions; Material physics with surface physics; Materialfysik med ytfysik;

    Abstract : Materials based on fullerenes and carbon nanotubes are very much different from most “traditional” materials, primarily because they are built from nanosized molecules with highly symmetry-dependent properties. Being the subject of a very active research field over the last twenty years, carbon nanostructures proved to be indeed extraordinary. READ MORE

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

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

    Abstract : 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. READ MORE