Phase behavior of a hard sphere Maier-Saupe nematogenic system in three dimensions

We present a detailed computer simulation and integral equation study of the phase behavior of a nematogenic system composed of hard spheres with embedded three-dimensional Maier-Saupe spins. For this well-known system, we map the gas-liquid equilibrium, which is coupled to a first-order isotropic-nematic transition. The anisotropic integral equation theory is found to yield excellent agreement with the simulation data within the fluid regime. Additionally, we determine the fluid-solid equilibrium transition by means of computer simulation.

Figure 1

(Color online) Integral equation and simulation results for the excess internal energy of the hard sphere Maier-Saupe fluid with and without external fields.

Figure 2

(Color online) Integral equation and simulation results for the pressure of the hard sphere Maier-Saupe fluid with and without external fields.

Figure 3

(Color online) Density dependence of the two-particle component of the longitudinal susceptibility determined via the RHNC-TZLMBW equations at $T^{*}=3.5$ and various external fields $W_0^{*}$, as labeled.

Figure 4

(Color online) Density histograms (upper figure) and chemical potential distribution (lower figure) in $NpT$ simulations of the Maier-Saupe fluid in the vicinity of the isotropic-nematic transition. The first-order equilibrium densities correspond to the two maxima (minima) of the density (chemical potential) histograms for the pressure at which the gas and liquid phase extrema reach equal values.

Figure 5

(Color online) Phase diagram of the Maier-Saupe fluid determined from an anisotropic integral equation and computer simulation. The error bars at most simulation points have the same size as the symbols.