Sökning: "High Energy Surface X-ray Diffraction"

Visar resultat 1 - 5 av 84 avhandlingar innehållade orden High Energy Surface X-ray Diffraction.

1. 1. On Surface Characteristics and Microstructural Development of Soft Magnetic Composite Powder and Components

   Författare :Christos Oikonomou; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; X-ray photoelectron spectroscopy; compaction; annealing; X-ray diffraction; soft magnetic composites; high resolution scanning electron microscopy; surface layers; magnetic testing; powder metallurgy; depth profiling; electron backscatter diffraction; focused ion beam; thickness determination; energy dispersive X-ray spectroscopy; microstructure;

   Sammanfattning : Soft Magnetic Composite (SMC) products manufactured by traditional Powder Metallurgical (PM) techniques, are strong candidate materials for electromagnetic applications. Their advantages are based on cost and energy efficient production methods, shape complexity realization and uniquely uniform and isotropic three dimensional (3D) magnetic properties. LÄS MER

3. 2. Studies of Phonons and Phase Transitions by Time-Resolved X-ray Diffraction

   Författare :Henrik Enquist; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; synchrotron radiation; ultrashort pulses; material science; phase transition; X-ray diffraction; phonon; X-ray detector;

   Sammanfattning : When light is used to study structures, the wavelength limits the size of the details that can be resolved. Visible light can be used to investigate structures as small as a micrometre in size. To study smaller structures a shorter wavelength is required. LÄS MER

4. 3. Surface Studies of Model Systems relevant for Pd and Ag Catalysts

   Författare :Natalia Martin; Synkrotronljusfysik; []
   Nyckelord :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;

   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

5. 4. Structure, Morphology, and Catalytic Properties of CuOx/CeO2 Model Catalysts

   Författare :Björn Skårman; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Synchrotron radiation; High-energy Diffraction; X-ray Absorption Fine Structure Spectroscopy.; Chemical technology and engineering; Kemiteknik och kemisk teknologi; Chemistry; Kemi; Material technology; Materiallära; materialteknik; X-ray photoelectron spectroscopy; Atomic force microscopy; Gatan Image Filter GIF ; Energy-filtered TEM; High-resolution electron microscopy; Inert gas condensation IGC ; rf Magnetron sputtering; Thermal activation; Batch reactor; Carbon monoxide oxidation; Surface sensitivity; Catalytic anisotropy; Growth; Nucleation; Topography; Roughness; Core-shell structures; Morphology; Nanostructured; Nanocomposite; Nanoparticles; Surface structure; Polycrystalline surfaces; Thin films; Copper oxide; Cerium dioxide CeO2 ; Ceria;

   Sammanfattning : Cerium dioxide, or ceria, is a chemically stable oxygen ion conducting material with a capacity to store and release oxygen, and is therefore extensively used in combustion catalysts. The Cu-Ce-O system has been identified as one of the most active catalysts for the combustion of carbon monoxide. LÄS MER

7. 5. Exploration of Non-Aqueous Metal-O2 Batteries via In Operando X-ray Diffraction

   Författare :Chenjuan Liu; Torbjörn Gustafsson; Laurence Hardwick; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Keywords: lithium-oxygen batteries; sodium-oxygen batteries; metal-air; in operando X-ray diffraction; cathode materials; Kemi med inriktning mot materialkemi; Chemistry with specialization in Materials Chemistry;

   Sammanfattning : Non-aqueous metal-air (Li-O2 and Na-O2) batteries have been emerging as one of the most promising high-energy storage systems to meet the requirements for demanding applications due to their high theoretical specific energy. In the present thesis work, advanced characterization techniques are demonstrated for the exploration of metal-O2 batteries. LÄS MER