In principle, most of the properties of solids can be determined by their electronic structures. So the understanding of electronic structures is essential. This thesis presents two classes of materials using ab initio method based on density functional theory. One is heavy metal compounds like Ta2AlC, ThO and the other one is hydrogen storage material namely MgH2 surfaces. The study of correlation and relativistic effects in Ta2AlC are presented. Based on our results, Ta2AlC is a weakly correlated system. Our study shows that the spin - orbital coupling does not play a very important role where as the other relativistic corrections such as mass velocity and Darwin terms have a significant effect on the electronic properties. The stability of rock salt like ThO has been proposed based on the first principle calculation. ThO can be stabilized under pressure. The driving force is the sd to f charge transfer in Th. We have investigated the energetics of hydrogen desorption from the MgH2 (110) and (001) surfaces. The doping of foreign metal elements and strain were used to reduce the dehydrogenation energy. The reduction in dehydrogenation energy is caused by the charge localization on the metal atoms which leads to destabilization and the weakening of metal - hydrogen bonds. / <p>QC 20130327</p>
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kth-120062 |
| Date | January 2013 |
| Creators | Sun, Weiwei |
| Publisher | KTH, Tillämpad materialfysik, Stockholm |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Licentiate thesis, comprehensive summary, info:eu-repo/semantics/masterThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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