MLC

Abstract

A purpose of this review is to give a systematic exposition of the Landau theory of phase transitions (LTPT). The construction of the Landau free energy expansion and the methods to identify the equilibrium structures will be discussed and illustrated with examples of phase transitions involving nematic- and smectic phases. Then it will be demonstrated how the Landau theory can be derived in a systematic way from (molecular) density functional theories, like mean field. This connection is especially attractive for it allows to view the LTPT as a simple tool to study bifurcation mechanisms, leading to phase transitions at the level of molecular modeling.