Caloric curve across the liquid-to-gas change for sodium clusters - art. no. 203402

The caloric curve for Na-139(+) has been measured from 100 K up to the temp erature where the clusters are boiling hot and spontaneously em it atoms. I n this limit the clusters form an evaporative ensemble, the temperature and energy of which have been determined. As the caloric curve of an atomic ga s with a finite number of atoms is known, one can construct the caloric cur ve for this finite system below and above the boiling point. A conjecture i s made on how to link the evaporative ensemble temperature of the free clus ter in vacuum to the boiling temperature of a finite system at a given pres sure. This allows one to determine the enthalpy of vaporization at the phas e transition of the finite system.