Dresden 2009 – wissenschaftliches Programm
DY 12.27: Poster
Dienstag, 24. März 2009, 14:30–16:30, P1A
Statistical mechanical description of polarizable liquid systems in electric field — •Semjon Stepanow and Thomas Thurn-Albrecht — Institut für Physik, Universität Halle, D-06099 Halle
We formulate the statistical mechanical description of liquid systems without permanent dipoles in an electric field in the E-ensemble, which is the pendant to the thermodynamic description in terms of the free energy at constant potential. The contribution of the electric field to the configurational integral QN(E) in the E-ensemble is given in an exact form as a factor in the integrand of QN(E). We also calculate the contribution of the electric field to the Ornstein-Zernike formula for the scattering function in the E-ensemble. As an application we calculate the shift of the critical temperature for the van der Waals gas in the electric field, and show that the shift is downward in E0-ensemble (constant charges) and upward in E-ensemble.