Kinetic contribution to the fast spinodal decomposition controlled by diffusion

Analysis of a model for fast spinodal decomposition controlled by diffusion is proposed. Using the concept of fast phase separation, an interpretation of a purely non-equilibrium contribution to the entropy of a spinodally decomposing system is given in terms of multi-component fluids and of magnetic dipole systems with non-vanishing inertia. Conditions for violation of the standard “hydrodynamic approximation” in the description of fast spinodal decomposition are formulated.