Based on classical density functional theory (DFT), we investigate the demixing phase transition of a two-dimensional, binary Heisenberg fluid mixture. The particles in the mixture are modeled as Gaussian soft spheres, where one component is characterized by an additional classical spin-spin interaction of Heisenberg type. Within the DFT we treat the particle interactions using a mean-field approximation. For certain magnetic coupling strengths, we calculate phase diagrams in the density-concentration plane. For sufficiently large coupling strengths and densities, we find a demixing phase transition driven by the ferromagnetic interactions of the magnetic species. We also provide a microscopic description (i.e., density profiles) of the resulting non-magnetic/magnetic fluid-fluid interface. Finally, we investigate the phase separation using dynamical density functional theory, considering both nucleation processes and spinodal demixing.
History
School
Science
Department
Mathematical Sciences
Citation
LICHTNER, K., ARCHER, A.J. and KLAPP, S.H.L., 2012. Phase separation dynamics in a two-dimensional magnetic mixture. Journal of Chemical Physics, 136 (2), 024502, 14pp.