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.
- Received 24 July 2000
DOI:https://doi.org/10.1103/PhysRevLett.86.1191
©2001 American Physical Society