EXPANSION OF FREE-ENERGY IN TERMS OF CORRELATION-FUNCTIONS WITHIN THE LANDAU-GINZBURG MODEL .2. CALCULATION IN 2-DIMENSIONAL AND 3-DIMENSIONAL CASES

The asymptotics of correlation functions and critical exponents are investigated within the Landau-Ginzburg phase transition model for ferroelectrics. The new method proposed is based on a subsequent account for fluctuations. Both analytical and numerical calculations are performed showing that the method gives nontrivial critical exponents. Moreover, precise values are obtained in the two-dimensional case below the phase transition point. The first-order phase transition is observed in the three-dimensional case.