Structural Classification of Thermotropic Liquid Crystals

Abstract

Most crystals transform directly into the liquid phase, so that the long-range translational order as well as the long-range orientational order of the molecules are destroyed simultaneously. However, if the constituent molecules have pronounced anisotropy of shape, the disappearance in one, two, or three dimensions of the long-range translational periodicity in the crystal may precede the collapse of the long-range orientational order; the intermediate phases are then referred to as liquid crystals.