References of "Humbert, Christophe"
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See detailInfluence of the metal electronic properties on the sum-frequency generation spectra of dodecanethiol self-assembled monolayers on Pt (111), Ag (111) and Au (111) single crystals
Dreesen, Laurent ULg; Humbert, Christophe; Celebi, M. et al

in Applied Physics B : Lasers & Optics (2002), 74

Infrared-visible sum-frequency generation (SFG) spectroscopy is performed at different visible wavelengths between 450 and 650 nm in order to investigate the interaction between metallic substrates (Pt ... [more ▼]

Infrared-visible sum-frequency generation (SFG) spectroscopy is performed at different visible wavelengths between 450 and 650 nm in order to investigate the interaction between metallic substrates (Pt, Ag and Au) and 1-dodecanethiol self-assembled monolayers. We show that such measurements provide a means to study the electronic properties of metals as well as the interference phenomena between the SFG signals from the adsorbate and the substrate. The common features of the three interfaces are the vibration modes of the terminal methyl groups. However, these resonances appear as peaks for Pt (111) and as dips in the case of Ag (111). Their shape is not modified when the visible wavelength is tuned between 450 and 650 nm. Moreover, the metal sum-frequency generation contribution is slightly modified in that spectral range. For Au (111) samples, the sum-frequency generation spectrum drastically evolves with the visible wavelength: the peak resonant sum-frequency generation signal at 450 nm becomes rather dip-shaped at 650 nm. The non-linear response of gold is also enhanced when the wavelength associated with the sum-frequency process is close to 480 nm. These results are interpreted on the basis of the metal electronic properties that are responsible for the non-resonant contribution to the SFG signal. [less ▲]

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See detailIR-visible sum-frequency vibrational spectroscopy of Biphenyl-3 methylene thiol monolayer on gold and silver: effect of the visible wavelength on the SFG spectrum
Humbert, Christophe; Dreesen, Laurent ULg; Mani, A. A. et al

in Surface Science (2002), 502-503

We measured IR-visible sum-frequency generation spectra of CH3-(C6H4)2-(CH2)3-S-H (Biphenyl-3) self-assembled monolayers on a silver and a gold substrate. For the latter substrate, we observed different ... [more ▼]

We measured IR-visible sum-frequency generation spectra of CH3-(C6H4)2-(CH2)3-S-H (Biphenyl-3) self-assembled monolayers on a silver and a gold substrate. For the latter substrate, we observed different interference patterns between the resonant signal of the CH vibration and the non-resonant contribution of the substrate as a function of the visible beam wavelength. The non-linear response of the gold substrate is enhanced around 480 nm corresponding to the s-d interband transition. Such effect is not observed for the silver substrate the interband transition of which is located out of the investigated visible spectral range of 450-700 nm. [less ▲]

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See detailEtude par spectroscopie de génération de la fréquence somme de l'interface méthanol-platine
Vidal, F.; Busson, B.; Six, C. et al

in J. Phys. IV France (2002), 12

La spectroscopie vibrationnelle non-linéaire par génération de la fréquence somme est une sonde particulièrement adaptée à l'étude des interfaces entre milieux denses. Cette technique a été appliquée à l ... [more ▼]

La spectroscopie vibrationnelle non-linéaire par génération de la fréquence somme est une sonde particulièrement adaptée à l'étude des interfaces entre milieux denses. Cette technique a été appliquée à l'étude de l'interface électrochimique monocristal de platine/solution acide de méthanol, système qui constitue un modèle de pile à combustible, dispositif où l'énergie chimique est directement convertie en énergie électrique. Les propriétés vibrationnelles dépendent fortement de l'orientation cristallographique de l'électrode de platine. [less ▲]

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See detailStudy of the metal-adsorbate interactions using SFG spectroscopy at different visible wavelengths
Dreesen, Laurent ULg; Humbert, Christophe; Celebi, Michael et al

Conference (2001, October)

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See detailSum-frequency generation characterisation of the water/polyethylene glycol interface
Dreesen, Laurent ULg; Humbert, Christophe; Hollander, Philippe et al

Poster (2001, June)

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See detailSum-frequency generation characterisation of the water/polyethylene glycol interface
Dreesen, Laurent ULg; Humbert, Christophe; Hollander, Philippe et al

Poster (2001, May)

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See detailSum-frequency generation characterisation of methanol, pentadecanoïc acid and water interfaces
Humbert, Christophe; Dreesen, Laurent ULg; Hollander, Philippe et al

Poster (2000, May)

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See detailSum-frequency generation characterisation of methanol-calcium fluoride and water-calcium fluoride interfaces
Dreesen, Laurent ULg; Humbert, Christophe; Hollander, Philippe et al

Poster (2000, April 03)

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