CO (a3Π) quenching at a metal surface: Evidence of an electron transfer mediated mechanism

Fabian Grätz; Daniel P Engelhart; Roman J V Wagner; Gerard Meijer; Alec M Wodtke; Tim Schäfer

doi:10.1063/1.4887777

CO (a3Π) quenching at a metal surface: Evidence of an electron transfer mediated mechanism

J Chem Phys. 2014 Jul 28;141(4):044712. doi: 10.1063/1.4887777.

Authors

Fabian Grätz¹, Daniel P Engelhart¹, Roman J V Wagner¹, Gerard Meijer², Alec M Wodtke¹, Tim Schäfer¹

Affiliations

¹ Max-Planck-Institut Für Biophysikalische Chemie, Karl Friedrich-Bonhoeffer-Institut, Am Fassberg 11, 37077 Göttingen, Germany.
² Fritz-Haber-Institut der Max-Planck-Gesellschaft, Abteilung Molekülphysik, Faradayweg 4-6, 14195 Berlin, Germany.

PMID: 25084942
DOI: 10.1063/1.4887777

Abstract

We observe a strong influence of molecular vibration and surface temperature on electron emission promoted by the de-excitation of metastable CO(a(3)Π) on a clean Au(111) surface using a molecular beam surface scattering apparatus. The de-excitation is independent of incidence translational energy. These observations appear incompatible with existing theories of metastable particle de-excitation on metal surfaces, which are based on the Auger effect. Instead, they strongly suggest a mechanism involving formation of a transient anion whose lifetime is similar to the vibrational period of the CO molecule.