Accelerated inertial regime in the spinodal decomposition of magnetic fluids.

Abstract

Furukawa predicted that at late times, the domain growth in binary fluids scales as (<i>t</i>) ∼ <i>t</i>^2/3, and the growth is driven by fluid inertia. The inertial growth regime has been highly elusive in molecular dynamics (MD) simulations. We perform coarsening studies of the (<i>d</i> = 3) Stockmayer (SM) model comprising of magnetic dipoles that interact <i>via</i> long-range dipolar interactions as well as the usual Lennard-Jones (LJ) potential. This fascinating polar fluid exhibits a gas-liquid phase coexistence, and magnetic order even in the absence of an external field. From comprehensive MD simulations, we observe the inertial scaling [(<i>t</i>) ∼ <i>t</i>^2/3] in the SM fluid for an extended time window. Intriguingly, the fluid inertia is overwhelming from the outset - our simulations do not show the early diffusive regime [(<i>t</i>) ∼ <i>t</i>^1/3] and the intermediate viscous regime [(<i>t</i>) ∼ <i>t</i>] prevalent in LJ fluids.