Negative heat capacity for a cluster of 147 sodium atoms.

  title={Negative heat capacity for a cluster of 147 sodium atoms.},
  author={M. Schmidt and R. Kusche and T. Hippler and J. Donges and W. Kronm{\"u}ller and B. von Issendorff and H. Haberland},
  journal={Physical review letters},
  volume={86 7},
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. 

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