000K  utf8
1100  $c2004
1500  eng
2050  urn:nbn:de:gbv:8-diss-9334
3000  Ramírez Garcia Claudia del Pilar
4000  Ab initio study of alkali diffusion and intercalation on transition metal dichalcogenides$hChristian-Albrechts-Universität zu Kiel  [Ramírez Garcia Claudia del Pilar]
4030  Kiel$nChristian-Albrechts-Universität zu Kiel
4209  The aim of this work was to understand how alkali metal atoms intercalate into transition metal dichalcogenides (TMDCs). To this end, a detailed investigation into the geometrical and electronic effects on TMDCs caused by adsorption and intercalation of alkali atoms was carried out by means of ab initio density-functional theory. The geometrical and electronic properties of clean TiSe_2 (0001) surface were studied. Also, the adsorption sites and diffusion of alkali atoms on TiSe_2 (0001) surface were computed and compared with those obtained at the van der Waals gap. The electron charge distribution caused by alkali atoms on TiSe_2 (0001) surface was analysed. The alkali coverage dependence of the physical properties adsorption energy, work function, and valence electron distribution was also studied. The question of whether the alkali atoms can reach the van der Waals gap from the plain surface through the atomic planes was addressed. Because of the huge energy barrier involved in this process (3.81 eV), this type of intercalation can be excluded. Thus, the experimentally found intercalation processes must be associated with defects, such as steps or dislocations at the surface. A model of alkali intercalation into TMDCs was obtained, namely via a (1 0 -1 0) step.
4950  https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-9334$xR$3Volltext$534
4961  https://macau.uni-kiel.de/receive/diss_mods_00000933
5051  530
5550  Ab-initio-Rechnung
5550  Adsorption
5550  Alkalimetall
5550  Alkali-Metall
5550  Dichte-Funktional-Theorie
5550  Diffusion
5550  Diffusion
5550  Gesamtenergieberechnung
5550  Interkalation
5550  Interkalation
5550  Lokale-Dichte-Approximation
5550  Pseudopotential
5550  Schichtkristallen
5550  Übergangsmetalldichalkogenide
5550  Uebergangs-Metall-Dichalcogenid