Temperature hysteresis in a phase transition corresponding to a growth and destruction of graphene islands on rhenium

It has been shown that the area occupied by graphene on the surface at the same temperature and carbon concentration in the bulk is significantly different at the equilibrium growth and destruction of graphene islands on a metal dissolving carbon in the bulk. In particular, graphene in equilibrium on rhenium carbonized at a temperature of 1830 K occupies 40% of the surface area at a temperature of 1875 K under the conditions of growth of islands and 80% under their destruction. It has been shown that this effect is explained within the previously developed three-phase model of the phase transition taking into account that only edge atoms of graphene islands, i.e., their perimeter, are in equilibrium.