Characterization of the Melting Transition in Two Dimensions at Vanishing External Pressure Using Molecular Dynamics Simulations

Daniel Asenjo; Fernando Lund; Simón Poblete; Rodrigo Soto; Marcos Sotomayor

doi:10.1103/physrevb.83.174110

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arXiv · 1101.4337

Characterization of the Melting Transition in Two Dimensions at Vanishing External Pressure Using Molecular Dynamics Simulations

Daniel Asenjo·Fernando Lund·Simón Poblete·Rodrigo Soto·Marcos Sotomayor

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Abstract

A molecular dynamics study of a two dimensional system of particles interacting through a Lennard-Jones pairwise potential is performed at 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.

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Daniel Asenjo, Fernando Lund, Simón Poblete, Rodrigo Soto, Marcos Sotomayor. 2011-03-18. Characterization of the Melting Transition in Two Dimensions at Vanishing External Pressure Using Molecular Dynamics Simulations. https://doi.org/10.1103/physrevb.83.174110

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