Regensburg 2016 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 14: Surface Chemical Dynamics

O 14.10: Vortrag

Montag, 7. März 2016, 17:30–17:45, S053

Inelastic Hydrogen Atom Scattering: Role of Electron-Hole Pair Excitations — •Oliver Bünermann, Hongyan Jiang, Yvonne Dorenkamp, and Alec Wodtke — Universität Göttingen, Institut für Physikalische Chemie, Tammannstr 6, 37077 Göttingen

Obtaining an atomic-level understanding of the dynamics of energy conversion at surfaces remains a complex and challenging area of modern research in physical chemistry. A general strategy to this field follows the lessons of gas-phase bimolecular chemical dynamics, where simple model systems are studied experimentally with great care while theoretical simulations are developed. One of the simplest systems to think of is Hydrogen atom scattering from a single crystalline surface. We built a new apparatus to experimentally investigate this model system with extraordinary precision. Laser photolysis is employed to produce a monochromatic H-atom beam. The H-atom beam strikes a single crystalline surface held in UHV. The kinetic energy and angular distributions of the scattered H-atoms are measured with extraordinary resolution employing Rydberg Atom Tagging.

Experimental results for scattering H-atoms from metal and insulator surfaces will be presented. In case of an insulator the scattering is nearly elastic while in case of metals strongly inelastic scattering is observed. Our results reveal that electron-hole-pair excitation is the dominate relaxation channel for H-atom translation in case of a metal surface, an interpretation supported by theoretical calculations [1].

[1] Buenermann, O et al., Science, DOI:10.1126/science.aad4972 (2015)