Characterization of the melting transition in two dimensions at vanishing external pressure using molecular dynamics simulations

Article

关键词: LENNARD-JONES;    ANISOTROPIC SOLIDS;    SYSTEMS;    ORDER;    PHASE;   

DOI  :  10.1103/PhysRevB.83.174110

来源: SCIE

【 摘 要 】

A molecular dynamics study of a two-dimensional system of particles interacting through a Lennard-Jones pairwise potential is performed at a fixed temperature and vanishing external pressure. As the temperature is increased, a solid-to-liquid transition occurs. When the melting temperature T-c is approached from below, there is a proliferation of dislocation pairs and the elastic constant approaches the value predicted by the KTHNY theory. In addition, as T-c is approached from above, the relaxation time increases, consistent with an approach to criticality. However, simulations fail to produce a stable hexatic phase using systems with up to 90,000 particles. A significant jump in enthalpy at T-c is observed, consistent with either a first order or a continuous transition. The role of external pressure is discussed.

【 授权许可】

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