Berlin 2015 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 64: New Methods
O 64.4: Poster
Mittwoch, 18. März 2015, 18:15–21:00, Poster A
Surface properties of CeO2(111) within kinetic Monte Carlo simulations — •Stefano Mattiello1, Stefan Kolling1, Marvin Lee Gusen2, Christian Heiliger2, and Herbert Oven3 — 1Technische Hochschule Mittelhessen, Gießen, Germany — 2I. Physikalisches Institut, Justus-Liebig-Universität Gießen, Germany — 3Physikalisch-Chemisches Institut, Justus-Liebig-Universität Gießen, Germany
Recently Kullgren and coworkers claim a incompatibility between density functional theory (DFT) and experimental results of Esch about the density and structure of the vacancies for the surface (111) of CeO2 under UHV condition and they assume that the claimed oxygen vacancies are in fact fluorine impurities. In order to examine the possibility of a significant fluorine contamination we perform a twice investigation of the ceria surface within kinetic Monte Carlo simulations. Firstly, assuming the formation of vacancies and neglecting fluorine impurities we find that this possibility is not totally incompatible with the relevant DFT results, if microscopic dynamics is considered. Secondly, we investigate the competition between fluorine and oxygen vacancies finding a direct correlation between fluorine and vacancies concentration. This may suggest, that the absence of vacancies and the presence of fluorine only should be unlikely.