Abnormal kinetic-energy fluctuations and critical behaviors in the microcanonical lattice gas model
(IN2P3-CNRS/ISMRA et Université) - F-14050 Caen cédex, France
2 GANIL (DSM-CEA/IN2P3-CNRS) - B.P.5027, F-14021 Caen cédex, France
Accepted: 6 March 2000
In this paper we present a microcanonical lattice gas model with a fluctuating volume. In the first-order liquid-gas phase transition region thermodynamical anomalies such as a back-bending in the caloric curve and a negative heat capacity are observed. This phenomenon induces abnormal kinetic-energy fluctuations and is associated with a critical fragment size distribution. The relevance of these findings for the experimental detection of a liquid-gas phase transition in finite systems is discussed.
PACS: 24.10.Pa – Thermal and statistical models / 64.60.Fr – Equilibrium properties near critical points, critical exponents / 64.70.-p – Specific phase transitions
© EDP Sciences, 2000