Influence of Pressure on Smectic A-Nematic Phase Transition

TL;DR

This paper develops a phenomenological model to analyze how pressure influences the smectic A-nematic phase transition, revealing a change from first to second order at a tricritical point consistent with experiments.

Contribution

It introduces a Landau-de Gennes model to describe pressure effects on the smectic A-nematic transition, highlighting the transition's change in order.

Findings

Transition changes from first to second order with pressure.

Tricritical point identified where transition order changes.

Model aligns with experimental observations.

Abstract

We propose a Landau-de Gennes phenomenological model to describe the pressure induced smectic A-nematic phase transition. The pressure induced smectic A phase transitions are discussed for varying coupling between orientational and translational order parameter. Increasing the pressure, the first order nematic-smectic A transition becomes second order at a tricritical point which agrees fairly with available experimental results.