X-Ray Studies of Tilted Hexatic Phases in Thin Liquid-Crystal Films

E. B. Sirota; P. S. Pershan; L. B. Sorensen; J. Collett

doi:10.1103/PhysRevLett.55.2039

X-Ray Studies of Tilted Hexatic Phases in Thin Liquid-Crystal Films

E. B. Sirota, P. S. Pershan, L. B. Sorensen, and J. Collett

Phys. Rev. Lett. 55, 2039 – Published 4 November 1985

Abstract

X-ray-diffraction studies of the structures and phase transitions of the tilted hexatic phases (smectic $F$ and smectic $I$ in thin liquid-crystal films of 4- $n$ -heptyloxybenzylidene-4-n- $n$ -heptylaniline (70.7) are reported. The measured correlation lengths were strongly anisotropic in both phases. The smectic- $I$ to smectic- $F$ transition is first order as expected from the symmetry change. The smectic- $F$ to smectic- $G$ transition is first order with strong pretransition effects and becomes nearly second order as the film thickness is decreased.

Received 22 January 1985

DOI:https://doi.org/10.1103/PhysRevLett.55.2039

Authors & Affiliations

E. B. Sirota and P. S. Pershan

Division of Applied Sciences, Harvard University, Cambridge, Massachusetts 02138

L. B. Sorensen

Department of Physics, University of Washington, Seattle, Washington 98195

J. Collett^*

Division of Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, and IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598