Sökning: "fermi surfaces"
Visar resultat 1 - 5 av 22 avhandlingar innehållade orden fermi surfaces.
1. III–V Nanowire Surfaces
Sammanfattning : This dissertation deals with the geometric and electronic structure of surfaces on III–V semiconductor nanowires (NWs). NWs made of InAs, GaAs, and InP have been studied using scanning tunneling microscopy/spectroscopy (STM/S), low energy electron microscopy (LEEM), photoemission electron microscopy (PEEM), and x-ray photoelectron spectroscopy (XPS). LÄS MER
2. Vibrational Spectroscopy of Surface Adsorbates on Metal Surfaces. Experiments and Calculations
Sammanfattning : This work deals with a detailed analysis of the vibrational spectra of methoxy (CH3O-) and ethoxy (CH3CH2O-) on W(110) and Cu(100) single crystal surfaces. By using theoretical ab initio quantum mechanical modeling, it is demonstrated that an unprecedented quantitative understanding of the vibrational frequencies of a surface adsorbate can be obtained. LÄS MER
3. Non-collinear Magnetism in d- and f-electron Systems
Sammanfattning : In this thesis, non-collinear magnetism has been studied by using density functional theory and the augmented plane wave method with local orbitals (APW+lo). Two conditions for non-collinear instabilities have been identified in this thesis. First, the Fermi energy should cut through both spin up and down states. LÄS MER
4. Electronic structure of clean and adsorbate-covered InAs surfaces
Sammanfattning : This thesis is the result of investigations regarding the processes in InAs III-V semiconductor surfaces induced by additional charge incorporated by adsorbates. The aim of the project is to study the development of the accumulation layer on the metal/InAs(111)A/B surfaces and its electronic structure. LÄS MER
5. Chemical Bonding of Hydrocarbons to Metal Surfaces
Sammanfattning : Using x-ray absorption spectroscopy (XAS), x-ray emission spectroscopy (XES) and x-ray photoelectron spectroscopy (XPS) in combination with density functional theory (DFT) the changes in electronic and geometric structure of hydrocarbons upon adsorption are determined. The chemical bonding is analyzed and the results provide new insights in the mechanisms responsible for dehydrogenation in heterogeneous catalysis. LÄS MER