Accelerated inertial regime in the spinodal decomposition of magnetic fluids

Furukawa predicted that at late times, the domain growth in binary fluids scales as l(t)similar to t(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 (d = 3) Stockmayer (SM) model comprising of magnetic dipoles that interact via 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 [l(t)similar to t(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 [l(t)similar to t(1/3)] and the intermediate viscous regime [l(t)similar to t] prevalent in LJ fluids.

Automated summary

Furukawa predicted that the growth of domains in binary fluids is l(t)similar to t(2/3) at late times, driven by fluid inertia. However, this inertial growth regime has been difficult to observe in molecular dynamics simulations. In this study, we performed coarsening studies using the Stockmayer (SM) model, which consists of magnetic dipoles interacting with long-range dipolar interactions and the Lennard-Jones (LJ) potential. Interestingly, we found that the SM fluid exhibits the inertial scaling [l(t)similar to t(2/3)] for an extended time period, without showing the early diffusive regime [l(t)similar to t(1/3)] and the intermediate viscous regime [l(t)similar to t] seen in LJ fluids.