Search for dissertations about: "clusters"

Showing result 1 - 5 of 873 swedish dissertations containing the word clusters.

  1. 1. Rare-gas Clusters Studied by Electron Spectroscopy : Structure of Heterogeneous Clusters and Effects of Electron Scattering on Auger Decay

    Author : Marcus Lundwall; Olle Björneholm; Gunnar Öhrwall; Maxim Tchaplyguine; Thomas Möller; Uppsala universitet; []
    Keywords : Physics; Nano-particles; Clusters; Heterogeneous clusters; Core-shell clusters; XPS; UPS; AES; Electron scattering; Radial structure; Surface structure; Surface sensitivity; Synchrotron radiation; Ne; Ar; Kr; Xe; Fysik;

    Abstract : In this Thesis experimental studies of nano-clusters using synchrotron radiation based photoelectron (UPS and XPS) and Auger Electron Spectroscopy (AES) are presented. The investigations may be divided into two parts where the first reports on the structure of heterogeneous two component clusters, and the second concerns electronic decay processes. READ MORE

  2. 2. Multicomponent Clusters/Nanoparticles : An Investigation of Electronic and Geometric Properties by Photoelectron Spectroscopy

    Author : Chaofan Zhang; Olle Björneholm; Maxim Tchaplyguine; Svante Svensson; Gerd Ganteför; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Clusters; Nanoparticles; Alloy; Atmospheric chemistry; Alkali halide; Transition metals; X-ray Photoelectron spectroscopy; Polarizability; Core-shell; Sandwich structure; MAX-lab; BESSY II;

    Abstract : Clusters/nanoparticles are aggregates of a “small” number of building blocks, atoms or molecules, ranging from two up to millions of atoms. Two main groups of clusters have been studied using photoelectron spectroscopy based on synchrotron radiation. READ MORE

  3. 3. Free Molecular and Metal Clusters Studied by Synchrotron Radiation Based Electron Spectroscopy

    Author : Aldana Rosso; Svante Svensson; Olle Björneholm; Maxim Tchaplyguine; Gunnar Öhrwall; Uwe Hergenhahn; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; nanoparticles; free clusters; molecular clusters; metal clusters; photoelectron spectroscopy; synchrotron radiation; local structure; core level spectroscopy; auger spectroscopy; heterogeneous clusters; nucleation; bromomethane; chloromethane; benzene; bromobenzene; chlorobenzene; potassium; sodium; simple metals; Physics; Fysik;

    Abstract : The main purpose of this Thesis is the experimental characterization of the electronic and geometric structures of objects called clusters. A cluster consists of a finite group of bound atoms or molecules. Due to its finite size, it may present completely different properties than those of the isolated atom and the bulk. READ MORE

  4. 4. Free Metal Clusters Studied by Photoelectron Spectroscopy

    Author : Tomas Andersson; Olle Björneholm; Maxim Tchaplyguine; Paolo Piseri; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; clusters; nanoparticles; electronic structure; photoelectron spectroscopy; synchrotron radiation; surface segregation; nanoalloys; size-dependence; metallicity; plasmons; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : Clusters are aggregates of a finite number of atoms or molecules. In the present work, free clusters out of metallic parent materials have been created and studied by synchrotron radiation-based photoelectron spectroscopy. The clusters have been formed and studied in a beam and the electronic structure of the clusters has been investigated. READ MORE

  5. 5. Photoelectron Spectroscopy on Atoms, Molecules and Clusters : The Geometric and Electronic Structure Studied by Synchrotron Radiation and Lasers

    Author : Torbjörn Rander; Olle Björneholm; Gunnar Öhrwall; Maxim Tchaplyguine; Matthias Neeb; Uppsala universitet; []
    Keywords : Atomic and molecular physics; Free clusters; Electron spectroscopy; Doped clusters; Laser excitation; Alkali metals; Electronic structure; Geometric structure; X-ray photoelectron spectroscopy XPS ; Resonant Auger spectroscopy RAS ; Near-threshold x-ray absorption fine structure NEXAFS ; Ultraviolet photoelectron spectroscopy UPS ; Detuning; Ultra-fast dissociation UFD ; Sodium; Potassium; Oxygen; Bromomethane; Argon; Xenon; Krypton; Molecular field splitting; Core hole lifetime; Core excitation; Atom- och molekylfysik;

    Abstract : Atoms, molecules and clusters all constitute building blocks of macroscopic matter. Therefore, understanding the electronic and geometrical properties of such systems is the key to understanding the properties of solid state objects. READ MORE