Title: THERMODYNAMIC AND KINETIC DESCRIPTION OF THE SECOND ORDER PHASE TRANSITIONS
Author(s): Yu.L.Klimontovich (Department of Physics, M.V.Lomonosov Moscow State University, Vorob'evy gory, 119899 Moscow, Russia; E-mail: ylklim@hklim.phys.msu.su)

Thermodynamic and kinetic description of phase transitions for the model of ferroelectrics based on the kinetic equation for the distribution function of values of the ``order parameter'', coordinates and time is considered.
For one-domain ferroelectrics, the self-consistent approximation for the first moment is used. The kinetic equation is reduced to the relaxation Ginsburg-Landau equation. The susceptibility is governed by the Curie law and the heat capacity has the jump.
Calculations are carried out for one-domain and polydomain ferroelectrics. In the first case, the self-consistent approximation for the first moment is used. In the second case, the self-consistent approximation for the second moment is carried out. In the last case, there is the jump of the susceptibility. The heat capacity is governed by the Curie law.
It is also shown that the Ornstein-Zernike formula is valid not for the space correlator of fluctuations but only for the temporal spectral density of the space correlator at zero frequency.
In the kinetic theory of the phase transition, all physical characteristics at the critical point have got finite values. Thus, the problem of the ``infinities'' is absent.

Comments: Figs. 0, Refs. 18, Tabs. 0.