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DOF phase separation of the Lennard-Jones fcc(111) surface

C. S. Jayanthi·Franck Celestini·Furio Ercolessi·Erio Tosatti
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Abstract

Recent lattice model calculations have suggested that a full-layered crystal surface may undergo, under canonical (particle-conserving) conditions, a preroughening-driven two-dimensional phase separation into two disordered flat (DOF) regions, of opposite order parameter. We have carried out extensive classical molecular dynamics (MD) simulations of the Lennard-Jones fcc(111) surface, to check whether these predictions are relevant or not for a realistic continuous system. Very long simulation times, a grid of temperatures from (2/3)Tm to Tm, and unusually large system sizes are employed to ensure full equilibrium and good statistics. By examining layer-by-layer occupancies, height fluctuations, sublattice order parameter and X-ray structure factors, we find a clear anomaly at ~0.83Tm. The anomaly is distinct from roughening (whose incipiency is also detected at ~0.94Tm), and is seen to be consistent with the preroughening plus phase separation scenario.

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C. S. Jayanthi, Franck Celestini, Furio Ercolessi, Erio Tosatti. 2000-04-18. DOF phase separation of the Lennard-Jones fcc(111) surface. https://doi.org/10.1016/s0039-6028(00)00550-1

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