title: Free-energy power expansion for orientationally ordered phases: energy and entropy.
abstract: We propose an approach to the description of orientational phase transitions that utilizes the specific features of orientational energy and entropy. The approach is applied to building a model for nematic phases in materials with nonpolar parallelepiped-type molecules with symmetry D(2h). The model operates with complex order parameters, generalizes the Landau-de Gennes theory, and predicts the existence of a biaxial nematic phase for the fourth-order expansion of free energy.
authors.affiliation: Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, USA.
authors.forename: Sergij V
authors.initials: SV
authors.lastname: Shiyanovskii