Sökning: "first-principles theory"

Visar resultat 1 - 5 av 176 avhandlingar innehållade orden first-principles theory.

1. 1. Catalytic Water Production from First-Principles Calculations

   Författare :Gustav Karlberg; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; platinum; Monte Carlo; first-principles; hydroxyl; transition metals; density functional theory DFT ; Metropolis; oxygen; water; water production reaction; hydrogen;

   Sammanfattning : The main subject of this thesis is the catalytic water production reaction on metal surfaces. This reaction is of great current interest due to its importance in fuel cells, a clean and efficient way to convert chemical energy into electrical. LÄS MER

3. 2. Structural and magnetic disorder in crystalline materials : a first principles study

   Författare :Davide Gambino; Björn Alling; Pavel Korzhavyi; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Disorder in crystalline materials can take different forms and originate from different sources. In particular, temperature introduces disorder in any kind of material. LÄS MER

4. 3. Effects of disorder in metallic systems from First-Principles calculations

   Författare :Christian Asker; Igor Abrikosov; Jörg Neugebauer; Linköpings universitet; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

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

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

   Sammanfattning : 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. LÄS MER

7. 5. Materials Design from First Principles : stability and magnetism of nanolaminates

   Författare :Martin Dahlqvist; Johanna Rosén; Nicola Spaldin; Linköpings universitet; []
   Nyckelord :;

   Sammanfattning : In this thesis, first-principles calculations within density functional theory are presented, with a principal goal to investigate the phase stability of so called Mn+1AXn (MAX) phases. MAX phases are a group of nanolaminated materials comprised of a transition metal (M), a group 12-16 element (A), and carbon or nitrogen (X). LÄS MER