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Applications of density functional theory for modeling metal-semiconductor contacts, reaction pathways, and calculating oxidation states |
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| Author: | Posysaev, Sergei1,2 |
| Organizations: |
1University of Oulu Graduate School 2University of Oulu, Faculty of Science, Physics |
| Format: | ebook |
| Version: | published version |
| Access: | open |
| Online Access: | PDF Full Text (PDF, 1.2 MB) |
| Persistent link: | http://urn.fi/urn:isbn:9789526221328 |
| Language: | English |
| Published: |
Oulu : University of Oulu,
2018
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| Publish Date: | 2018-11-30 |
| Thesis type: | Doctoral Dissertation |
| Defence Note: | Academic Dissertation to be presented with the assent of the Faculty of Science, University of Oulu, for public discussion in the Auditorium IT 116, on December 14th, 2018 at 12 oâclock noon. |
| Tutor: |
Professor Matti Alatalo |
| Reviewer: |
Professor Bernardo Barbiellini Professor Kalevi Kokko |
| Opponent: |
Professor Marcel Sluiter |
| Kustos: |
Professor Matti Alatalo |
| Description: |
AbstractDensity functional theory (DFT) is a well-established tool for calculating the properties of materials. The volume of DFT-related publications doubles every 5â6 years, which has resulted in the appearance of continuously growing open material databases, containing information on millions of compounds. Furthermore, the results of DFT computations are frequently coupled with experimental ones to strengthen the computational findings. In this thesis, several applications of DFT related to physics and chemistry are discussed. The conductivity between MoSâ and transition metal nanoparticles is evaluated by calculating the electronic structure of two different models for the nanoparticles. Chemical bonding of Ni to the MoSâ host is proven by the systemâs band alignment. To meet the demand for cleaner fuel, the applicability of the (103) edge surface of molybdenum disulfide in relation to the early stages of the hydrodesulfurization (HDS) reaction is considered. The occurrence of the (103) edge surface of molybdenum disulfide in the XRD patterns is explained. A method for calculating oxidation states based on partial charges using open materials databases is suggested. We estimate the applicability of the method in the case of mixed valence compounds and surfaces, showing that DFT calculations can be used for the estimation of oxidation states. see all
TiivistelmĂ€Tiheysfunktionaaliteoria (density functional theory, DFT) on yleisesti kĂ€ytetty työkalu laskennallisessa materiaalitutkimuksessa. DFT:llĂ€ tuotettujen julkaisujen mÀÀrĂ€ kaksinkertaistuu 5â6 vuoden vĂ€lein, minkĂ€ johdosta kĂ€ytettĂ€vissĂ€ on jatkuvasti kasvava mÀÀrĂ€ avoimia materiaalitietokantoja, joihin on talletettu miljoonien yhdisteiden ominaisuuksia. DFT-laskujen tuloksia tĂ€ydennetÀÀn myös usein kokeellisilla tuloksilla. TĂ€ssĂ€ työssĂ€ tarkastellaan tiheysfunktionaaliteorian sovelluksia fysiikassa ja kemiassa. MoSâ:n ja metallisten nanopartikkelien vĂ€listĂ€ johtavuutta on tutkittu mallintamalla erilaisia nanopartikkeleita. Nikkelin ja MoSâ:n vĂ€linen kemiallinen sidos selittyy systeemin energiavöiden kohdistumisella. MoSâ:n (103)-pinnan soveltuvuutta rikinpoistoreaktion varhaisissa vaiheissa on tutkittu tarkoituksena löytÀÀ uusia menetelmiĂ€ puhtaan polttoaineen tuottamiseksi. Myös (103)-pinnan esiintyminen röntgendiffraktiokuvissa selitetÀÀn. TyössĂ€ on myös esitetty menetelmĂ€ hapetustilojen laskemiseksi tietokannoista löytyvien laskettujen varausjakaumien avulla. MenetelmĂ€n soveltuvuutta on tarkasteltu erilaisille yhdisteille ja pinnoille. TĂ€mĂ€ tarkastelu osoittaa, ettĂ€ DFT-tuloksia voidaan kĂ€yttÀÀ hapetustilojen laskemiseen. see all
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| Series: |
Report series in physical sciences |
| ISSN: | 1239-4327 |
| ISSN-L: | 1239-4327 |
| ISBN: | 978-952-62-2132-8 |
| ISBN Print: | 978-952-62-2131-1 |
| Issue: | 123 |
| Subjects: | |
| Copyright information: |
© University of Oulu, 2018. This publication is copyrighted. You may download, display and print it for your own personal use. Commercial use is prohibited. |