Failure of thermodynamics near a phase transition
Résumé
In the vicinity of a first-order phase transition, the equation of state might be different when the extensive variable is controlled instead of the intensive one, violating the uniqueness of thermodynamics. A sufficient condition for this nonequivalence to survive at the thermodynamical limit is worked out for classical systems. If energy consists of a kinetic and a potential part, the microcanonical ensemble does not converge towards the canonical ensemble when the kinetic heat capacity is larger than the modulus of the negative interaction heat capacity.