Observation of electron gas cooling in free sodium clusters.
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.
Maier
M
M
Fakultät für Physik, Universität Freiburg, Stefan-Meier-Strasse 21, D-79104 Freiburg, Germany.
Wrigge
G
G
Hoffmann
M Astruc
MA
Didier
P
P
von Issendorff
B
B