Graphite melting: Atomistic kinetics bridges theory and experiment

The graphite melting temperature remains poorly determined despite the considerable effort accomplished since the work of Bundy (1963) [1]. The absence of a consensus on its melting temperature at normal conditions has been considered as a technical problem that motivated more and more sophisticated experiments. The experimental evidences of the maximum on the graphite melting curve resulted in the liquid-liquid phase transition hypothesis for liquid carbon. However this hypothesis still requires a sound evidence. In this work using atomistic methods we focus on the kinetics of graphite melting and show that the experimental puzzles can be resolved by considering the graphite melting as a process in the non-equilibrium superheated solid. The unusually slow melting kinetics results in the existence of the superheated graphite at the microsecond timescale and thus biases the measurements of its equilibrium melting temperature.