On the Landau theory of phase transitions: a hierarchical dynamic model.
The  Landau theory of phase transitions has been re-examined under the framework of a modified mean field theory in ferroelectrics. By doing so, one can see that there are two atomic movements involved in the ferroelectric phase transition; the first corresponds to the vibration of the crystalline lattice, which will render phonon mode softening at the critical point, and the second represents the slow evolution of a partially ordered nematic phase formed by the cooperative behavior of high-temperature structure precursors. In this hierarchical dynamic structure, the former fast dynamics could be significantly modulated by the latter slow dynamics in the vicinity of the Curie temperature; it then turns out that it is the behavior of the nematic phase on approaching the critical point that makes the Landau theory deviate from experimental observations.
Department of Mechanical and Aerospace Engineering, The State University of New York, Buffalo, NY 14260, USA. youweifu@buffalo.edu
John Y
JY
Fu
D000465:Algorithms; D003198:Computer Simulation; D050866:Liquid Crystals / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D044367:Phase Transition