Molecular dynamics simulation of the capillary leveling of a glass-forming liquid

I. Tanis (1) , K Karatasos , Thomas Salez (2)

1 LEPMI - Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces
2 LOMA - Laboratoire Ondes et Matière d'Aquitaine

We study the evolution of square-wave patterns at the free surface of a glass-forming binary Lennard-Jones mixture over a wide temperature range, by means of molecular dynamics simulations. Particular emphasis is given on the surface diffusion which is found to be considerably faster with respect to the bulk, below the glass-transition temperature, in agreement with experimental and simulation data for organic glasses. Specifically, the pattern's amplitude is recorded as a function of time and the associated decay rate is extracted. Layer-resolved dynamic analysis further reveals that surface diffusion governs the relaxation below the glass transition temperature. Diffusion coefficients of the surface particles are larger than those in the bulk by a factor that reaches $10^4$ at the lowest temperature studied. These deviations grow upon cooling.

Domaines: Matière Molle [cond-mat.soft]; Science des matériaux [cond-mat.mtrl-sci]; Systèmes désordonnés et réseaux de neurones [cond-mat.dis-nn]; Mécanique statistique [cond-mat.stat-mech]; Mécanique des fluides [physics.class-ph]; Mécanique des matériaux [physics.class-ph]; Mécanique des solides [physics.class-ph]; Dynamique des Fluides [physics.flu-dyn]

I. Tanis, K Karatasos, Thomas Salez. Molecular dynamics simulation of the capillary leveling of a glass-forming liquid. 2019. ⟨hal-01909064v1⟩