Data di Pubblicazione:
2006
Citazione:
Core level spectroscopy of free titanium clusters in supersonic beams / P.G.C. Piseri, T. Mazza, G.A. Bongiorno, C. Lenardi, L. Ravagnan, F. Della Foglia, F. Di Fonzo, M. Coreno, M. De Simone, K.C. Prince, P. Milani. - In: NEW JOURNAL OF PHYSICS. - ISSN 1367-2630. - 8(2006 Aug 18), pp. 136.136-1-136.136-8.
Abstract:
Synchrotron radiation x-ray absorption spectroscopy (XAS) is one of the most powerful techniques to interrogate the local electronic structure and chemical status of bulk and nanostructured systems. The application of this technique to the study of size effects in free clusters of transition metal atoms would advance substantially fundamental knowledge of nano-objects and the
tailoring of their magnetic and catalytic properties. To date core level spectroscopy
of free transition metal clusters has been out of reach due to the lack of a cluster
source able to produce clusters in the gas phase with a density suitable for
synchrotron radiation sources. Here we demonstrate the XAS characterization
of free titanium clusters in a supersonic molecular beam. We use a high-intensity cluster beam source coupled to a synchrotron beamline to investigate the size dependence of core level excitation of Tin clusters in the mass range 15 < n < 1000. The x-ray absorption of Tin evolves from a multi-peaked complex structure similar to that of Ti atoms towards spectra characterized by two main
absorption features as in bulk titanium. The intensities and the fine structure of the
spectra are size dependent showing regularities compatible with geometric shell
closings and the presence of a structural transition at about 540 atoms/cluster.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
core levels ; metal clusters ; nanostructured materials ; titanium ; X-ray absorption spectra
Elenco autori:
P.G.C. Piseri, T. Mazza, G.A. Bongiorno, C. Lenardi, L. Ravagnan, F. Della Foglia, F. Di Fonzo, M. Coreno, M. De Simone, K.C. Prince, P. Milani
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