Frustrated Spin-Gas Model for Doubly Reentrant Liquid Crystals

Abstract

A mechanism, based on the competition between short-range positional order and longrange antiferroelectric order, is presented for reentrant liquid crystals. Antiferroelectric frustration is inherent to the triangular close packing of layers normal to the molecular axis, but is lifted at intermediate temperatures by positional disorder. Phase diagrams evaluated by using prefacing transformations include the doubly reentrant case exhibiting, as temperature is lowered, nematic, bilayer smectic, reentrant nematic, and monolayer smectic phases.