Resonant vibrational excitation of H-GaAs(001) in HREELS

Citation
J. Eggeling et al., Resonant vibrational excitation of H-GaAs(001) in HREELS, SURF SCI, 481(1-3), 2001, pp. 135-142
Citations number
13
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
SURFACE SCIENCE
ISSN journal
0039-6028 → ACNP
Volume
481
Issue
1-3
Year of publication
2001
Pages
135 - 142
Database
ISI
SICI code
0039-6028(20010610)481:1-3<135:RVEOHI>2.0.ZU;2-C
Abstract
High resolution electron energy loss spectroscopy (HREELS) has been used to study the adsorption of hydrogen on the Ga-rich GaAs(0 0 1)-c(8 x 2) surfa ce. Particular attention is focused on the inelastic electron scattering pr ocesses associated with this adsorbate system and the characteristics of ea ch spectral feature. Extensive HREELS measurements, and comparison with the oretical predictions based on pure dipole scattering, provide clear evidenc e for the involvement of a negative ion resonance at 8 eV in the excitation of the Ga-H stretching vibration at 1900 cm(-1). High frequency features a t similar to 2120 cm(-1) are shown to be predominantly the combination of a coupled plasmon-phonon mode and the Ga-H stretch. At low hydrogen coverage s, a contribution to this loss feature can be assigned to an As-H stretchin g mode. (C) 2001 Elsevier Science B.V. All rights reserved.