Textural transformations in islands on free standing Smectic C* liquid crystal films

TL;DR

This paper investigates the textural transformations in islands within free-standing Smectic C* liquid crystal films, combining experimental observations with a linear stability analysis to understand the transition from bend to spiral textures.

Contribution

It introduces a theoretical phase diagram predicting texture transformations in islands, validated by experimental observations in Smectic C* liquid crystal films.

Findings

Pure bend texture transitions to a reversing spiral at a critical size

Boundary condition changes induce distinct spiral textures

Theoretical phase diagram aligns with experimental results

Abstract

We report on and analyze the textural transformations in islands, thicker circular domains, floating in very thin free standing chiral Smectic C* liquid crystal films. As an island is growing, an initial pure bend texture of the c-director changes into a reversing spiral at a critical size. Another distinct spiral texture is induced by changing the boundary condition at the central point defect in the island. To understand these transformations from a pure bend island, a linear stability analysis of the c-director free energy is developed, which predicts a state diagram for the island. Our observations are consistent with the theoretical phase diagram.