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O: Fachverband Oberflächenphysik
O 69: Poster: Solid-Liquid Interfaces
O 69.12: Poster
Wednesday, March 29, 2023, 18:00–20:00, P2/EG
DFT calculation of the Sad diffusion energy barriers on Ag(100) in the presence of Br coadsorbates — •Sönke Buttenschön and Eckhard Pehlke — Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
Coadsorbed halides are known to affect the adatom diffusion on metal surfaces [1]. As a prerequisite for theoretical modelling of the Sad diffusion on Ag(100) as a function of Br coverage, we have calculated the effect of single and multiple Br coadsorbates on the Sad adsorption energy as well as on the energy at the transition geometry along the Sad diffusion path for various Br coadsorbate configurations with Br coverages up to 0.25. The density functional total-energy calculations have been carried through with PWscf and PWneb from the Quantum ESPRESSO package [2]. The dipole moment of Sad is negative. It is larger in magnitude at the transition state (TS) than at the adsorption position. Averaged over the considered S-Br configurations the absolute value of the Sad dipole moment has a tendency to decrease with Br coverage in qualitative agreement with a depolarization model. After similar averaging, for the TS configurations the superposition of individual STS-Br pair interaction energies tends to overestimate the actual STS-Br interaction. Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), project 504552981.
[1] B. Rahn, O. M. Magnussen, ChemElectroChem 5, 3073 (2018).
[2] P. Giannozzi et al., J. Phys. Condens. Matter 21, 395502 (2009), ibid. 29, 465901 (2017).