Search for dissertations about: "first-principles"

Showing result 6 - 10 of 280 swedish dissertations containing the word first-principles.

2. 6. Effects of disorder in metallic systems from First-Principles calculations

   Author : Christian Asker; Igor Abrikosov; Jörg Neugebauer; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Iron; Nickel; Magnesium; Manganese; Molybdenum; Zirconium; Elastic Constants; High pressure; Earth s core; Density-functional theory; Ab-initio; First-Principles; Core-level shifts; Molecular Dynamics; Phonons; Dynamical Instability; Condensed matter physics; Kondenserade materiens fysik; Computational physics; Beräkningsfysik;

   Abstract : In this thesis, quantum-mechanical calculations within density-functional theory on metallic systems are presented. The overarching goal has been to investigate effects of disorder. In particular, one of the properties investigated is the bindingenergy shifts for core electrons in binary alloys using different theoretical methods. READ MORE

4. 7. Amorphous and crystalline functional materials from first principles

   Author : Leyla Isaeva; Olle Eriksson; Jörg Neugebauer; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; first-principles theory; lattice dynamics; phase transitions; amorphous materials; tribology; ultrafast magnetism;

   Abstract : This thesis deals with various functional materials from first-principles methods and is divided into two major parts according to the underlying atomic structure of the system under study. The first part of the thesis deals with the temperature-induced structural phase transitions in metallic  β'-AuZn and perovskite oxide LiOsO3. READ MORE

5. 8. First Principles Studies of Carbon Based Molecular Materials

   Author : Bin Gao; Yi Luo; Piero Decleva; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; first principles simulations; carbon based molecular materials; X-ray spectroscopies; Theoretical chemistry; Teoretisk kemi;

   Abstract : The aim of this thesis was to investigate carbon based molecular materials at first principles levels. Special attention has been paid to simulations of X-ray spectroscopies, including near edge X-ray absorption fine structure (NEXAFS), X-ray photoelectron, and X-ray emission spectroscopy, which can provide detailed information about core, occupied and unoccupied molecular orbitals of the systems under investigation. READ MORE

6. 9. First principles simulations of electron transport at the molecule-solid interface

   Author : Hao Ren; Yi Luo; Nicolás Lorente; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; first principles; electron transport; solid surface; inelastic electron tunneling; Quantum chemistry; Kvantkemi;

   Abstract : In this thesis I concentrate on the description of electron transport properties of microscopic objects, including molecular junctions and nano junctions, in particular, inelastic electron tunneling in surface-adsorbate systems are examined with more contemplations. Boosted by the rapid advance in experimental techniques at the microscopic scale, various electric experiments and measurements sprung up in the last decade. READ MORE

7. 10. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis

   Author : Joakim Nyman; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; first principles; trapping; conductivity; grain boundary; segregation; pyrochlore; space charge; solid oxide fuel cell; depletion; electrolyte; La2Zr2O7; oxygen vacancy; BaZrO3; proton; DFT; point defect; perovskite; acceptor;

   Abstract : Fuel cells are devices which convert chemical energy into electrical energy cleanly and efficiently. Development of fuel cells compatible with hydrocarbon fuels would make more efficient use of present fossil and renewable fuels, and also enable progress towards a future hydrogen economy. READ MORE