Search for dissertations about: "scanning tunneling microscopy"

Showing result 21 - 25 of 70 swedish dissertations containing the words scanning tunneling microscopy.

  1. 21. Surface Studies of Model Systems relevant for Pd and Ag Catalysts

    Author : Natalia Martin; Synkrotronljusfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; High Pressure X-ray Photoelectron Spectroscopy; X-ray Photoelectron Spectroscopy; alumina; Ag; NiAl; Pd; catalysis; model system; Surface X-ray Diffraction; Low Energy Electron Diffraction; Scanning Tunneling Microscopy; Fysicumarkivet A:2014:Martin;

    Abstract : This PhD thesis reports on investigations of the atomic scale structure of model catalysts relevant for the catalytic oxidation of CO and methane over Pd, and NOx reduction over silver-alumina, important reactions in automotive catalysts. By using complementary experimental techniques such as X-ray Photoelectron Spectroscopy, High Pressure X-ray Photoelectron Spectroscopy, Surface X-ray Diffraction, Low Energy Electron Diffraction, Infrared Spectroscopy, and Scanning Tunneling Microscopy, combined with theoretical calculations, the work presented in this thesis aims at an atomistic characterization of the active sites for silver-alumina and Pd model catalysts which may help to the design of new and improved catalysts. READ MORE

  2. 22. Above and Below Graphene: Nanoparticle Chemistry and Interface Reactions

    Author : Elin Grånäs; Synkrotronljusfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Graphene; Scanning tunneling microscopy; X-ray photoelectron spectroscopy; Adsorption; Nanoparticles; Ir 111 ; Surface science;

    Abstract : The work presented in this dissertation addresses two main topics: (i) graphene supported nanoparticles and their stability upon gas adsorption, and (ii) intercalation of different molecules under graphene and their reactions under graphene. From an interplay of X-ray photoelectron spectroscopy, scanning tunneling microscopy, low energy electron diffraction, and density functional theory an atomic scale understanding of both the nanoparticles and the intercalated structures is obtained. READ MORE

  3. 23. Probing Atomic Scale Structure and Catalytic Properties of Cobalt Oxide Model Catalysts

    Author : Alif Arman; Synkrotronljusfysik; []
    Keywords : catalysis; model systems; Co3O4 111 ; Co3O4 100 ; CoO 111 ; X-ray photoelectron spectroscopy; Scanning tunneling microscopy; Fysicumarkivet A:2017:Arman;

    Abstract : Cobalt oxides are known to be active catalysts for a number of chemical reactions, but very little is known about the atomic scale processesresponsible for the activity. The research presented in this thesis is focused on obtaining an atomic scale understanding of the chemistry of wellcharacterizedcobalt oxide model catalyst surfaces consisting of pristine and defective CoO and Co3O4 thin films with the (111) and (100)terminations supported by Ag(100), Ir(100), and Au(111) single crystal surfaces. READ MORE

  4. 24. Elastic and inelastic scattering effects in conductance measurements at the nanoscale : A theoretical treatise

    Author : Peter Berggren; Jonas Fransson; Wolfgang Belzig; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Scattering theory; Scanning tunneling microscopy; tunnel junctions; molecular graphene; paramagnetic molecules; spin interaction; nano electromechanical system; Josephson junction; superconductivity; chaos; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : Elastic and inelastic interactions are studied in tunnel junctions of a superconducting nanoelectromechanical setup and in response to resent experimental superconducting scanning tunneling microscope findings on a paramagnetic molecule. In addition, the electron density of molecular graphene is modeled by a scattering theory approach in very good agreement with experiment. READ MORE

  5. 25. Oxidation of some Late Transition Metal Surfaces: Structural Studies from UHV to Atmospheric Pressure

    Author : Johan Gustafson; Synkrotronljusfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Kondenserade materiens egenskaper:struktur; phase equilibria; crystallography; thermal and mechanical properties; Condensed matter:stucture; density functional theory; scanning tunneling microscopy; surface x-ray diffraction; high resolution core level spectroscopy; low energy electron diffraction; metal surfaces; oxidation; catalysis; egenskaper termiska och mekaniska ; kristallografi; fasjämvikt;

    Abstract : The oxidation of Rh, Pd and Pt is studied under conditions ranging from ultra high vacuum to ambient pressures, with emphasis on a complete understanding of the geometry of the various oxide structures found. The investigations use a combination of various experimental methods, including high resolution core level spectroscopy, low energy electron diffraction, surface x-ray diffraction and scanning tunneling microscopy, as well as density functional theory calculations. READ MORE