Phase coexistence of a Stockmayer fluid in an applied field

Abstract

We examine two aspects of Stockmayer fluids which consists of point dipoles\nthat additionally interact via an attractive Lennard-Jones potential. We\nperform Monte Carlo simulations to examine the effect of an applied field on\nthe liquid-gas phase coexistence and show that a magnetic fluid phase does\nexist in the absence of an applied field. As part of the search for the\nmagnetic fluid phase, we perform Gibbs ensemble simulations to determine phase\ncoexistence curves at large dipole moments, $\\mu$. The critical temperature is\nfound to depend linearly on $\\mu^2$ for intermediate values of $\\mu$ beyond the\ninitial nonlinear behavior near $\\mu=0$ and less than the $\\mu$ where no\nliquid-gas phase coexistence has been found. For phase coexistence in an\napplied field, the critical temperatures as a function of the applied field for\ntwo different $\\mu$ are mapped onto a single curve. The critical densities\nhardly change as a function of applied field. We also verify that in an applied\nfield the liquid droplets within the two phase coexistence region become\nelongated in the direction of the field.\n