Search for dissertations about: "Fermi surfaces"

Showing result 1 - 5 of 22 swedish dissertations containing the words Fermi surfaces.

2. 1. III–V Nanowire Surfaces

   Author : Martin Hjort; NanoLund: Centre for Nanoscience; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; low energy electron microscopy; scanning tunneling spectroscopy; scanning tunneling microscopy; surface; III–V semiconductor materials; nanowire; photoemission electron microscopy; photoelectron spectroscopy; Fysicumarkivet A:2014:Hjort;

   Abstract : 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). READ MORE

4. 2. Vibrational Spectroscopy of Surface Adsorbates on Metal Surfaces. Experiments and Calculations

   Author : Ragnar K Ásmundsson; Kemisk fysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; ab initio electronic structure calculations; Fermi resonance; vibrational spectroscopy; Reflection absorption infrared spectroscopy; Fourier transform infrared spectroscopy; Cu 100 and W 110 single crystal surfaces; Physics; Fysik;

   Abstract : 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. READ MORE

5. 3. Non-collinear Magnetism in d- and f-electron Systems

   Author : Raquel Lizárraga Jurado; Olle Eriksson; Lars Nordström; Axel Svane; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Non-collinear magnetism; spin spirals; first principles; density functional theory; Fermi surfaces; electronic structure; f-electron systems; Fysik;

   Abstract : 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. READ MORE

6. 4. Electronic structure of clean and adsorbate-covered InAs surfaces

   Author : Karolina Szamota-Leandersson; Ulf Otto Karlsson; Vladimir Chab; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; angle-resolved photoemission; electronic structure; accumulation layer; adatoms; reconstruction; Surfaces and interfaces; Ytor och mellanytor;

   Abstract : 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. READ MORE

7. 5. Chemical Bonding of Hydrocarbons to Metal Surfaces

   Author : Henrik Öström; Anders Nilsson; Phil Woodruff; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Adsorption; hydrocarbon; core-level; spectroscopy; Physics; Fysik;

   Abstract : 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. READ MORE