The Clausius-Mossotti Phase Transition in Polar Liquids

TL;DR

This paper investigates the phase transition behavior of polar liquids, like water, using the Clausius-Mossotti model, revealing domain formation and stability issues related to high polarizability.

Contribution

It introduces a phase transition framework for polar liquids based on the Clausius-Mossotti equation, highlighting domain structures and instability in highly polarizable molecules.

Findings

Identification of instability in the polarization equation for high polarizability liquids.

Description of domain-based ordered phases similar to Dicke superradiance.

Use of an 'equal area' construction to analyze stable phases.

Abstract

The conventional Clausius-Mossotti polarization equation of state is known to be unstable for polar liquids having molecules with high polarizability. Room temperature water is an important example. The instability in the polarization equation of state is of the typical loop form requiring an ``equal area'' construction for studying the stable ordered phase. The ordered phase of a Clausius-Mossotti polar liquid then consists of domains each having a net polarization. The polarization may vary in direction from domain to domain. The ordered phases are quite similar to those previously discussed on the basis of Dicke superradiance.