Search for dissertations about: "vibrational modes"

Showing result 6 - 10 of 62 swedish dissertations containing the words vibrational modes.

  2. 6. ZnO Quantum Dots : Size Dependent Optical, Vibrational and Photoelectrochemical Properties

    Author : Jesper Jacobsson; Tomas Edvinsson; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ZnO; nanoparticels; quantum dots; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

    Abstract : This thesis is devoted to quantum dots of ZnO in the size regime 2.5-10 nm.The focus is directed towards their size dependent properties with specialemphasis on the optical, vibrational and photocatalytic properties. The particleswere synthesized by hydrolysis in alkaline zinc acetate solution. READ MORE

  4. 7. Dynamic local structural symmetries and luminescence properties of the yellow emitting phosphor Ce3+-doped Y3Al5O12

    Author : Yuan-Chih Lin; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; free electron laser; neutron scattering; vibrational spectroscopy; phosphor; light emitting diode; luminescence; thermal quenching; garnet;

    Abstract : This thesis centers on investigations of the local structure and vibrational properties of the oxide garnet Y3Al5O12 (YAG), which when substituted with a few percent of the activator ion Ce3+ to replace Y3+ (Y3−xCexAl5O12, YAG:Ce3+) is one of the most important phosphors for solid state lighting. The study builds on a comprehensive analysis of the nature of the phonons and localized vibrational modes in YAG:Ce3+ and how these depend on the Ce3+ concentration and temperature and how they affect key optical properties, such as the intensity and frequency of the emitted light. READ MORE

  5. 8. Strong Light-Matter Coupling: the Road from Conventional to Cavity-Free Polaritons

    Author : Adriana Canales Ramos; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fabry-Pérot microcavities; self-hybridized polaritons; Mie modes; Strong and ultrastrong coupling; Lorentz resonances; decay rates; cavity-free polaritons; Casimir force; 2D–crystals; plasmons; water droplets.; self-assembled microcavities;

    Abstract : The interaction between light and matter is fundamental in perceiving and understanding the world. The interaction is typically weak, meaning light only perturbs matter without changing its properties. READ MORE

  6. 9. Determination of binary fission-fragment yields in the reaction 251Cf(nth, f) and Verification of nuclear reaction theory predictions of fission-fragment distributions in the reaction 238U(n, f)

    Author : Evert Birgersson; Andreas Oberstedt; Stephan Oberstedt; Nicolae Carjan; Örebro universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; nuclear reactions; mass energy distributions; fission modes; fission-fragment spectroscopy; 251Cf nth; f ; 238U n; f ; Physics; Fysik; Fysik; Physics;

    Abstract : Neutron-induced fission has been studied at different excitation energies of the compound nucleus by measurements on the two fissioning systems, 252Cf* and 239U*.For the first time, the light fission fragment yields from the reaction 251Cf(nth, f) have been measured with high resolution. READ MORE

  7. 10. Molecular electronic,  vibrational and rotational motion in optical and x-ray fields

    Author : Sergey Gavrilyuk; Faris Gelmukhanov; Stephane Carniato; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; x-ray; nonlinear optics; photobleaching; recoil; anisotropy; Auger; Chemical physics; Kemisk fysik;

    Abstract : The subject of this theoretical  study is the role ofelectronic structure as well as of rotational and vibrational motionson interactions between molecules and electromagnetic radiation,ranging from optical to x-ray. The thesis concerns both linear and nonlinear regimes of the light-matter interaction. READ MORE