1.
Phys Rev Lett
; 86(7): 1191-4, 2001 Feb 12.
Article
in English
| MEDLINE
| ID: mdl-11178041
ABSTRACT
There exists a surprising theoretical prediction for a small system: its microcanonical heat capacity can become negative. An increase of energy can-under certain conditions-lead to a lower temperature. Here we present experimental evidence that a cluster containing exactly 147 sodium atoms does indeed have a negative microcanonical heat capacity near its solid to liquid transition.