In this work we investigate the deexcitation process of a slow metastable helium atom (He*) in its triplet state on simple metal surfaces. We compute the electronic properties of the interacting He*-metal (jellium-like) system, using the embedding Green's function method, within the framework of density functional theory. The Auger deexcitation rates are calculated at different distances from the surface using the Fermi golden rule, and the energy distribution of the emitted electrons is obtained by integrating the Auger rates along the classical trajectory followed by the atom in the scattering process. We present the results for three metal surfaces (Al, Na, and Cs) which are sufficiently different to span the distinct deexcitation mechanisms taking place when the He* interacts with the surface: resonant ionization + Auger neutralization for high work function substrates, and Auger deexcitation for low work function ones. Our results for the deexcitation spectral profiles are in good agreement with the experimental ones. (c) 2005 Elsevier B.V. All rights reserved.

Trioni, M., Butti, G., Bonini, N., Brivio, G. (2005). Metastable helium spectroscopy on simple metals: Comparison between low and high work function substrates. SURFACE SCIENCE, 587(1-2), 121-127 [10.1016/j.susc.2005.04.040].

Metastable helium spectroscopy on simple metals: Comparison between low and high work function substrates

BRIVIO, GIANPAOLO
2005

Abstract

In this work we investigate the deexcitation process of a slow metastable helium atom (He*) in its triplet state on simple metal surfaces. We compute the electronic properties of the interacting He*-metal (jellium-like) system, using the embedding Green's function method, within the framework of density functional theory. The Auger deexcitation rates are calculated at different distances from the surface using the Fermi golden rule, and the energy distribution of the emitted electrons is obtained by integrating the Auger rates along the classical trajectory followed by the atom in the scattering process. We present the results for three metal surfaces (Al, Na, and Cs) which are sufficiently different to span the distinct deexcitation mechanisms taking place when the He* interacts with the surface: resonant ionization + Auger neutralization for high work function substrates, and Auger deexcitation for low work function ones. Our results for the deexcitation spectral profiles are in good agreement with the experimental ones. (c) 2005 Elsevier B.V. All rights reserved.
Articolo in rivista - Articolo scientifico
Green's function methods; electron density; excitation spectra calculations; jellium models; density functional calculations; auger ejection; adatoms; alkali metals; metallic surfaces
English
ago-2005
587
1-2
121
127
none
Trioni, M., Butti, G., Bonini, N., Brivio, G. (2005). Metastable helium spectroscopy on simple metals: Comparison between low and high work function substrates. SURFACE SCIENCE, 587(1-2), 121-127 [10.1016/j.susc.2005.04.040].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/3963
Citazioni
  • Scopus 4
  • ???jsp.display-item.citation.isi??? 4
Social impact