Peculiarities of Defective Formations in Heterophase Regions of the Thermotropic Phase Transitions in Liquid Crystals

Abstract

A unique feature of phase transitions in liquid crystalline materials is the availability of heterophase regions. In such regions, the simultaneous coexistence of high temperature and low temperature phases takes place. Thermal mobility and temperature gradient in the heterophase regions lead to the appearance of various types of defective formations in the aligned and non-aligned textures of liquid crystalline materials. In the present work, the morphologic, structural, and optical peculiarities of defective formations and non-homogeneities, which appear in the heterophase regions of phase transitions, are investigated. The singular points, disclination, inversion walls, droplets, and confocal formations are objects of the investigations herein. The heterophase regions of the direct and reverse nematic isotropic liquid and smectic A isotropic liquid, smectic C isotropic liquid, and smectic C* isotropic liquid thermotropic phase transitions are created by the original method, that is, the capillary temperature wedge method. Crystallo-optics and crystallo-physics methods are used in this work.