Sökning: "low energy electron diffraction"
Visar resultat 16 - 20 av 109 avhandlingar innehållade orden low energy electron diffraction.
16. Electron Energy Loss Spectroscopy of III-Nitride Semiconductors
Sammanfattning : This Licentiate Thesis covers experimental and theoretical investigations of the bulk plasmon response to different compositions and strain states of group III-nitride materials. Investigated materials were grown using magnetron sputtering epitaxy and metal organic chemical vapour deposition and studied by Rutherford backscattering spectrometry, X-ray diffraction, electron microscopy and electron energy loss spectroscopy (EELS). LÄS MER
17. Surface Studies of Model Systems relevant for Pd and Ag Catalysts
Sammanfattning : 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. LÄS MER
18. Oxidation of some Late Transition Metal Surfaces: Structural Studies from UHV to Atmospheric Pressure
Sammanfattning : 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. LÄS MER
19. Characterizing cavity containing materials using electron microscopy : A study of metal oxides, mesoporous crystals and porous material containing nanosized metal-particles
Sammanfattning : This thesis concerns the characterization of novel materials by utilizing electron microscopy techniques. The examined materials contain cavities with certain attributes that enables desired properties for applications such as gas separation, catalysis and fuel cells. LÄS MER
20. Surface analysis of low dimensional materials : revealing their electronic properties by advanced spectroscopy
Sammanfattning : Low-dimensional materials (0D, 1D, 2D) have been widely used to develop modern miniaturized (micro- and nano-) technology. The use of these materials come from their extraordinary optical, electrical, thermal, and mechanical properties, which are very different from the bulk crystal. LÄS MER