POLARIZATION CHARACTERISTICS FROM SFG SPECTRA OF CLEAN AND REGULATIVELY OXIDIZED NI(100) SURFACES ADSORBED BY PROPIONATE AND FORMATE

Citation
T. Yuzawa et al., POLARIZATION CHARACTERISTICS FROM SFG SPECTRA OF CLEAN AND REGULATIVELY OXIDIZED NI(100) SURFACES ADSORBED BY PROPIONATE AND FORMATE, Surface science, 416(1-2), 1998, pp. 1090-1094
Citations number
29
Language
INGLESE
art.tipo
Letter
Categorie Soggetti
Chemistry Physical
Journal title
ISSN journal
0039-6028
Volume
416
Issue
1-2
Year of publication
1998
Pages
1090 - 1094
Database
ISI
SICI code
0039-6028(1998)416:1-2<1090:PCFSSO>2.0.ZU;2-G
Abstract
Experiments have been carried out on propionate and formate adsorbed o n clean and regulatively oxidized Ni(100) surfaces to scrutinize the n otion that the polarization characteristics of infrared-visible sum fr equency generation (SFG) signals of molecules on metallic surfaces are different from those due to molecules on insulating surfaces. Both pr opionate and formate give signals only for p-polarized visible pulses on clean metal and oxygen-saturated surfaces, but signals due to s-pol arized visible pulses appeared from the propionate-covered surface as soon as the surface was covered with a monolayer of NiO(100). Vibratio nal peaks of propionate were located at 2887, 2945, and 2988 cm(-1) an d were assigned to the symmetric stretching mode of CH2 group, the sym metric stretching mode of CH3 group, and the degenerate stretching mod e of CH3 group, respectively. The peak of the surface formate was loca ted at 2938 cm(-1) on the clean metal surface, but another band appear ed at 2860 cm(-1) on oxide-layered surfaces. The causes of this appear ance of the (sp) polarization signals by the presence of the NiO layer are discussed. (C) 1998 Elsevier Science B.V. All rights reserved.