Brevets |
Hocine Khemliche, P. R., Patrick Rousseau. (2012). Device and method for characterizing surfaces.
Résumé: A method of characterizing surfaces comprises the steps of:
directing a beam (2) of neutral atoms or molecules on a surface (3) for characterizing; and
detecting in position-sensitive manner the neutral atoms or molecules of said beam that have been diffused forwards by said surface (3) for characterizing;
the properties of said beam (2) being selected in such a manner that at least some of said neutral atoms or molecules that are diffused forwards are diffractive by said surface for characterizing.
A device for implementing such a method comprises means (1) for generating such a beam (2) of neutral atoms or molecules and position-sensitive detector means (4) for detecting the neutral atoms or molecules that are diffused forwards by said surface (3) for characterizing.
date de priorité: 7 juil. 2006
EP2044423A2, US20090250600, WO2008003865A2, WO2008003865A3
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Peer-reviewed Publications |
Cassimi, A., Ikeda, T., Maunoury, L., Zhou, C. L., Guillous, S., Mery, A., Lebius, H., Benyagoub, A., Grygiel, C., Khemliche, H., Roncin, P., Merabet, H., & Tanis, J. A. (2012). Dynamics of charge evolution in glass capillaries for 230-keV Xe23+ ions. Phys. Rev. A, 86(6), 062902.
Résumé: We have measured the transmission of 230-keV (10-keV/q) Xe23+ ions through insulating tapered glass capillaries of microscopic dimensions. The dynamics of charging and discharging processes have been investigated, evidencing an unexpected slow alignment of the beam along the capillary axis. Oscillations of the exiting beam position have been observed during the charging process associated to the formation of charge patches on the capillary inner walls. The emerging ions are guided with a characteristic guiding angle falling on a universal curve proposed for PET polymer nanocapillaries. This result, very similar to the channeling process, is somewhat surprising in view of the significant differences between the straight nanocapillary polymer foils and the tapered microscopic single glass capillary used here. The transmitted ions show no evidence of energy loss or charge changing except for the production of a small neutral fraction that was determined to be due to ions that had become neutralized to form atoms rather than due to photon emission. These results thus test and confirm the validity of transmission and guiding and provide insight into the dynamics of higher-energy ions than have been previously studied in this regard, allowing a determination of the maximum energy for which the guiding process might occur.
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Lalmi, B., Khemliche, H., Momeni, A., Soulisse, P., & Roncin, P. (2012). High resolution imaging of superficial mosaicity in single crystals using grazing incidence fast atom diffraction. J. Phys. Condens. Matter., 24(44), 442002.
Résumé: A new table top technique is used to simultaneously analyze the local morphology of crystalline surfaces as well as the misalignment of large scale domains at the topmost surface layer. The approach is based on fast atom diffraction at grazing incidence (GIFAD); the diffraction pattern yields the structural characteristics and the topology of the surface electronic density with atomic resolution. If superficial mosaicity is present, diffraction patterns arising from each mosaic domain can be distinguished, providing high sensitivity to the properties of each of the domains. Taking NaCl(001) as an example, we observe a discrete tilt angle distribution of the mosaic domains following an arithmetic progression with a 0.025 degrees +/- 0.005 degrees difference; a twist mosaic angle of 0.09 degrees +/- 0.01 degrees is also observed.
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Prato, M., Toccafondi, C., Maidecchi, G., Chaudhari, V., Harish, M. N. K., Sampath, S., Parodi, R., Esaulov, V. A., & Canepa, M. (2012). Mercury Segregation and Diselenide Self-Assembly on Gold. JOURNAL OF PHYSICAL CHEMISTRY C, 116(3), 2431–2437.
Résumé: We have investigated the self-assembly of didecyldiselenide on gold containing mercury using X-ray photoelectron spectroscopy, cyclic voltammetry and infrared spectroscopy. The analysis of intensity and chemical shift of selected Se, Hg, and Au photoelectron lines on samples with increasing Hg content, show that didecyldiselenide adsorption strongly contributed to segregation of bulk Hg to the surface. The voltammetry results support this conclusion and suggest the formation of Hg-Au surface amalgam. The Hg surface segregation effect must be related to the restructuring of the surface following initial adsorption, and to the strong selenophilicity of Hg. The reflectance absorbance infrared spectroscopy studies show that the molecular layer on Hg-Au substrates lacks good order.
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Chapitres de Livres |
Vladimir A.Esaulov. (2012). Low Energy Ion Scattering and Recoiling Spectroscopy in Surface Science. (Vol. 51, pp. 423–460). Springer Series in Surface Science. Springer-Verlag.
Résumé: This chapter presents an overview of low energy ion scattering spectroscopy and time of flight scattering and recoiling spectroscopy for the study of the structure and composition of surfaces as well as of fundamental ion surface interaction processes. The emphasis is on basic concepts regarding scattering, energy losses and charge transfer phenomena and experimental aspects involved in measurements of ion energies and time of flight measurements of scattered atoms. Some examples are provided to illustrate the type of information that can be obtained.
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