Berlin 2018 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 11: Topical session (Symposium MM): Hydrogen in Materials

MM 11.3: Vortrag

Montag, 12. März 2018, 16:45–17:00, H 0107

First-principles study of hydrogen related defects in titanium dioxide — •Mohsen Sotoudeh¹, Marian Bongers², Vladimir Roddatis², Jakub Čížek³, Carsten Nowak², Martin Wenderoth⁴, Peter Blöchl^1,2, and Astrid Pundt² — ¹Institute for Theoretical Physics, Clausthal University of Technology, Leibnizstr. 10, 38678 Clausthal-Zellerfeld, Germany — ²Institut für Materialphysik, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany — ³Department of Low-temperature Physics, Charles University in Prague, V Holešovičkách 2, 18000 Praha 8, Czech Republic — ⁴IV. Physikalischen Institut, Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany

Titanium dioxide (rutile) under hydrogen loading has been studied using first-principles calculations. In particular, we studied the defect electrochemistry near the interface with a metal. Defects related to oxygen vacancies and hydrogen have been investigated for different Fermi-levels. The band-gap underestimation in density-functional theory has been corrected. The nature of the electronic structure of the defects have been explored in detail. The defect concentration near the interfaces and their changes under hydrogen loading have been investigated. The calculated defect concentrations and the defect electronic structure explain experimental EELS spectra measured under hydrogen loading. We provide a mechanistic picture of the underlying chemical processes.

The work has been supported by the DFG through SFB 1073, projects B03, C03 and C06 as well via the Heisenberg grant PU131/9-2.