title: Observation of electron gas cooling in free sodium clusters.
abstract: Free size-selected Na+(n) (n = 16-250) clusters have been studied by femtosecond pump-probe photoelectron and photofragmentation spectroscopy. Thermal electron emission from the hot electron gas was used to monitor the energy transfer from the electronic system to lattice vibrations. The electron-phonon coupling constants determined for the different sizes can be described by the radius dependent function g(R) = (2.3 + 114 A2/R2) X 10(16) W/m3K. No strong quantum size effect was observed even for the smallest cluster size.
authors.affiliation: Fakultät für Physik, Universität Freiburg, Stefan-Meier-Strasse 21, D-79104 Freiburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Maier
authors.forename: G
authors.initials: G
authors.lastname: Wrigge
authors.forename: M Astruc
authors.initials: MA
authors.lastname: Hoffmann
authors.forename: P
authors.initials: P
authors.lastname: Didier
authors.forename: B
authors.initials: B
authors.lastname: von Issendorff