Journal of Physical Studies 4(4), 424–430 (2000)
DOI: https://doi.org/10.30970/jps.04.424

THE PROPERTIES OF A NONUNIFORM ATOMIC FLUID IN THE ELECTRIC FIELD. THE GRADIENT APPROXIMATION

O. V. Derzhko^{1,2}, V. M. Myhal^{2}
^{1}Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine
1 Svientsitskii Str., Lviv, UA-79011, Ukraine
^{2}The Ivan Franko National University of Lviv, Chair of Theoretical Physics,
12 Drahomanov Str., UA-79005, Ukraine

On the basis of the already suggested density functional of the grand thermodynamical potential (J. Phys. Stud. {\bf 1,} 402 (1997)) a problem concerning the properties of a nonuniform fluid of the two-level atoms in the external electrical field is considered. The calculations are performed within the frames of the gradient approximation which is valid for the temperatures only slightly lower than the critical temperature. The temperature dependence of the surface tension, the dependence of the nucleation (cavitation) barrier on the density of the saturated vapour (the liquid under tensile stress) are obtained. These results are compared with the ones obtained with the help of the nonlocal density functional. The influence of the electric field on the properties of a nonuniform atomic fluid is discussed.

PACS number(s): 64.70.Fx, 82.65.Dp, 62.60Nh, 64.60.Qb