Solidification of 2D simple monatomic system: molecular dynamics simulations

Solidification of the melted two-dimensional square lattice structure forming system is studied using molecular dynamics simulations. The initial model of 6400 atoms interacting via the square potential proposed by Rechstmann et al. (Phys. Rev. E, 73:011406, 2006) is cooled down from the melt at two different cooling rates. The research reveals the differences in the evolution of structure and thermodynamics of the system upon cooling from the melt. At the cooling rate of $${10}^{-7}$$ per MD step, the phase transition temperature is found to be $${T}_{C}=0.50$$, while it is $${T}_{g}=0.43$$ at the cooling rate of $${10}^{-5}$$ per MD step. Atomic mechanism of solidification of the system is analyzed via studying of the occurrence and growth of solid-like atoms upon cooling from the melt. Three characteristic temperatures of solidification are proposed. There is an evidence of the first-order phase transition behavior of the crystallization of the 2D melt