title: Negative heat capacity for a cluster of 147 sodium atoms.
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.
authors.affiliation: Fakultät für Physik, Universität Freiburg, H.Herderstrasse 3, D-79104 Freiburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Schmidt
authors.forename: R
authors.initials: R
authors.lastname: Kusche
authors.forename: T
authors.initials: T
authors.lastname: Hippler
authors.forename: J
authors.initials: J
authors.lastname: Donges
authors.forename: W
authors.initials: W
authors.lastname: Kronmüller
authors.forename: B
authors.initials: B
authors.lastname: von Issendorff
authors.forename: H
authors.initials: H
authors.lastname: Haberland