Thermodynamic properties of concentrated ferrofluids and the modified mean­field conception

E. A. Elfimova - E. D. Ekaterinchuk - A. Yu. Solovyova - A. O. Ivanov

Institute of Mathematics and Computer Sciences, Ural Federal University, 51 Lenin av., Ekaterinburg 620000, Russia

Abstract
The thermodynamic properties of the dipolar hard sphere fluid are studied using theory and simulation. A new theory is derived using a convenient mathematical approximation for the Helmholtz free energy relative to that for the hard sphere fluid. Dipolar hard spheres provide a basic model for ferrofluids, and the predictions of thermodynamic functions for dipolar coupling constants λ = 1 and λ = 2 show excellent agreement with simulation results, even at the highest value of the particle volume fraction. Figs 4, Refs 21