Condensed Matter Physics, 2006, vol. 9, No. 4(48), p. 703-708, English
DOI:10.5488/CMP.9.4.703
Title:
A microscopic theory of
photonucleation: Density functional approach to the properties of
a fluid of two-level atoms, a part of which is excited
Author(s):
 
| O.Derzhko
(Institute for Condensed Matter Physics of the National
Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011
Lviv, Ukraine)
,
|
 
| V.Myhal
(The Ivan Franko National University of
L'viv, Department for Theoretical Physics, 12 Drahomanov Street,
79005 L'viv, Ukraine)
|
We use the density functional method
to examine the properties of the nonuniform (two-phase) fluid of two-level atoms,
a part of which is excited.
From the analysis of the equation of state of a gas of two-level atoms,
a part of which is excited,
the following density functional of the grand thermodynamical potential emerges
Ω[ρ(r)] =ΩCS[ρ(r)]
-6σ3a(c1,T)π-1
∫|r1-r2|≥
2σdr1dr2
ρ(r1)ρ(r2)|r1-{\bf{r}}_2|-6
with
a(c1,T)
=32-1a2v(E1-E0)
(c0-c1+2c0c1E1-E0[kT]-1)
(here ΩCS[ρ(r)] is the
Carnahan-Starling term, σ is the atom radius,
v=4/3πσ3, c1 is the concentration of excited
atoms, c0+c1=1, E1-E0 is the excitation energy and a is
the dimensionless parameter which characterizes the atom). We use
this expression to calculate the nucleation barrier for
vapor-to-liquid phase transition in the presence of excited atoms.
Key words:
photonucleation,
nucleation barrier,
density functional approach
PACS:
64.70.Fx, 82.65.Dp, 62.60.Nh, 64.60.Qb
|