title: Caloric curves of small fragmenting clusters.
abstract: The kinetic energy release distribution of neutral atoms emitted from photoexcited clusters Sr(+)(n) with n=4-15, has been obtained by time-of-flight velocity dispersion. The deduced temperature is plotted as a function of the excitation energy. For small sizes n<7 a general increase is observed. For cluster sizes larger than n=9, the deduced caloric curves first increase, and then show evidence of a plateau regime as excitation energy increases. This limiting temperature in neutral atom ejection is consistent with a bound cluster-vapor phase transition in a microcanonical system.
authors.affiliation: Laboratoire Aimé Cotton CNRS, Université Paris-Sud, Bâtiment 505, F-91405 Orsay Cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Bréchignac
authors.forename: Ph
authors.initials: P
authors.lastname: Cahuzac
authors.forename: B
authors.initials: B
authors.lastname: Concina
authors.forename: J
authors.initials: J
authors.lastname: Leygnier