Physical origins of temperature continuity at an interface between a crystal and its melt.

We justify and discuss the physical origins for the assumption of temperature continuity at crystal/melt interfaces by performing atomistic simulations. We additionally answer why the crystal/melt interfaces differ from the typical solid/liquid interfaces, which usually exhibit dissimilarities and a resulting temperature drop. We present results for pure silver modeled using the embedded-atom method and Lennard-Jones potential function and contrast the results with each other. We find that the temperature continuity at an interface between a crystal and its melt originates from the perfect vibrational coupling, which is caused by the interfacial structural diffusivity. This study provides fundamental insights into the heat transfer for cases of extremely large heat flux and thermal gradients occurring during rapid melting and solidification. The findings additionally determine the role of rough surfaces in manipulating the thermal conductance in nanodevices.