Local orientational order in the Stockmayer liquid

TL;DR

This paper investigates the phase behavior of the Stockmayer fluid using a novel local orientational order parameter, revealing a second-order phase transition from a disordered to an oriented fluid phase.

Contribution

It introduces a new order parameter sensitive to local dipole co-orientation and maps the phase diagram highlighting a second-order transition.

Findings

Identification of a second-order phase transition

Development of a novel local orientational order parameter

Phase diagram for the Stockmayer fluid

Abstract

Phase behaviour of the Stockmayer fluid is studied with a method similar to the Monte-Carlo annealing scheme. We introduce a novel order parameter which is sensitive to the local co-orientation of the dipoles of particles in the fluid. We exhibit a phase diagram based on the behaviour of the order parameter in the density region 0.1 \leq {\rho}\ast \leq 0.32. Specifically, we observe and analyse a second order locally disordered fluid \rightarrow locally oriented fluid phase transition.