Stable states in the radiant heat transfer of the near field for two parallel slabs

In this paper, we study the dynamics of the radiative heat transfer of between two slabs. In these systems, depending on the type of slabs and the thermal interaction they have with their surroundings, they can have one or several stable states in the phase space. It can be seen that in these systems, quantities such as distance and thickness affect the states of these systems. We show that the distance between the slabs greatly affects the slabs reaching equilibrium. he Temperature of slabs in systems which has one equilibrium states, reach this state, regardless of the initial temperatures. However, systems with phase-change materials, could have several fixed points in their phase space. If the phase space of the system contains several fixed points, the final state of the system will be determined by the initial temperature of the slabs.