Condensed Matter Physics, 2013, vol. 16, No. 2, p. 23604:123
DOI:10.5488/CMP.16.23604
arXiv:1307.2030
Title:
Liquid gas phase transition at and below the critical point
Author(s):

I.R. Yukhnovskii
(Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine)
,


V.O. Kolomiets
(Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine)
,


I.M. Idzyk
(Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine)

This article is a continuation of previous works (see Yukhnovskii I.R. et al., J. Stat. Phys, 1995, 80, 405 and references therein), where we have described the behavior of a simple system of interacting particles in the region of temperatures at and about the critical point, T>=T_{c}. Now we present a description of the behavior of the system at the critical point T_{c}, η_{c}) and in the region below the critical point. The calculation is carried out from the first principles. The expression for the grand canonical partition function is brought to the functional integrals defined on the set of collective variables. The Isinglike form is singled out. Below T_{c}, when a gasliquid system undergoes a phase transition of the first order, i.e., boiling, a "jump" occurs from the "extreme" high probability gas state to the "extreme" high probability liquid state, releasing or absorbing the latent heat of the transition. The phase equilibria conditions are also derived.
Key words:
liquidgas phase transition, critical point, collective variables
PACS:
64.70.F, 64.60.F, 05.70.Jk
