title: Molecular theory of the tilting transition in smectic liquid crystals with weak layer contraction and diffused cone orientational distribution.
abstract: A molecular field theory of the smectic-A-smectic-C transition has been developed for smectics with a diffused cone orientational distribution of molecules (volcano-like distribution function) in the smectic-A phase and anomalously weak layer contraction in the smectic-C phase. Orientational order parameters and smectic layer spacing have been calculated numerically as functions of temperature and compared with the results obtained using a model with a standard Maier-Saupe-type distribution function that has been considered before. A molecular theory of the electroclinic effect in chiral smectics has also been developed using the recently proposed simple biaxial interaction potential. A comparison has been made between the absolute values and temperature variations of the electroclinic coefficient obtained using the volcano model, the model with Maier-Saupe-type distribution, and the orthodox cone model proposed by de Vries. It has been shown that the model with a conventional "sugar loaf" type orientational distribution function in the smectic-A phase is sufficient to describe the main properties of smectics with anomalously weak layer contraction.
authors.affiliation: Department of Mathematics and Statistics, University of Strathclyde, Livingstone Tower, Richmond Street, Glasgow, Scotland, United Kingdom.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Osipov
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Pająk
mesh_terms: D003198:Computer Simulation; D050866:Liquid Crystals / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D044367:Phase Transition