1971/09/01 by W. L. McMillan · 4 citations
Materials Science · Chemistry · Computer Science · #Liquid Crystal Research Advancements #Molecular spectroscopy and chirality #Nonlinear Dynamics and Pattern Formation
paper · doi:10.1103/physreva.4.1238
openalex publication_date 1971/09/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Maier-Saupe model of the nematic phase with an orientational order parameter is extended to the smectic A phase by introducing a new order parameter, the amplitude of a density wave in the direction of the nematic preferred axis. Self-consistent equations for the two order parameters are derived from an anisotropic model interaction and are solved numerically. We calculate the order parameters, the entropy, and the specific heat as a function of temperature for several values of dimensionless interaction strength \ensuremathα for the smectic A phase. The transition temperatures plotted versus \ensuremathα provide a theoretical phase diagram which resembles experimental plots of transition temperature versus alkyl chain length for homologous series of compounds. The model qualitatively reproduces chemical trends in transition entropies. Experiments are suggested to measure the order parameters in the smectic A phase.