Application of the generalized Landau ansatz to second order phase transitions

Abstract

The ansatz ofAmit et al. with expansion coefficients which can be nonanalytic functions of either the temperature or the order parameter is used to predict the generalized susceptibility (compressibility) and the surface tension belowT _c and the critical isotherm atT _c from the specific heat, the order parameter at the coexistence curve, and the coherence length. The results agree within 50% with experiments on different phase transitions in ferromagnets, classical gases, quantum gases, binary mixtures, and superfluid helium. The ansatz can be written in two different versions; their results differ only by logarithmic factors.