Electron emission spectra of thermal collisions of He metastable atoms with Au(111) and Pt(111) surfaces: Evidence for Penning ionization

Journal Article · Thu Oct 15 04:00:00 EDT 2009 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.80.040901· OSTI ID:21316321

Masuda, S; Sasaki, K; Sogo, M; Aoki, M ^[1]; Morikawa, Y ^[2]

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1. Department of Basic Science, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro, Tokyo 153-8902 (Japan)
2. Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

Electron emission spectra obtained by thermal collisions of He*(2{sup 1}S and 2{sup 3}S) atoms with Au(111) and Pt(111) surfaces were measured to clarify the electronically excited atom-metal interactions. It has been recognized that the metastable atoms de-excite on ordinary noble- and transition-metal surfaces via resonance ionization (RI) followed by Auger neutralization (AN) without no indication of Penning ionization (PI). Our data show that this traditional criterion partially breaks down in the He*-Au(111) collision system. The local electronic states near the surface were examined by first-principles calculations using density functional theory. It reveals that the itinerant sp states are significantly spilled out toward the vacuum compared to the localized 5d states, and their asymptotic features play a crucial role in determining the branching ratio between PI and RI+AN.

• OSTI ID: 21316321
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 4 Vol. 80; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ASYMPTOTIC SOLUTIONS
ATOMS
BRANCHING RATIO
COLLISIONS
DENSITY FUNCTIONAL METHOD
ELECTRON EMISSION
GOLD
INTERACTIONS
IONIZATION
METASTABLE STATES
PLATINUM
RESONANCE
SPECTRA
SURFACES