The effect of atom mismatch on the fragility of supercooled Lennard-Jones binarymixtures

Abstract

The shear viscosity of the well-known binary Lennard-Jones mixture issimulated under constant temperature and constant volume conditions(NVT) by a molecular-dynamics (MD) method. The effect of atomic size mismatch on thefragility parameter and glass-forming ability is studied. The fragility parameters calculatedfrom shear viscosity data decrease with the increment of the atomic size mismatch. Thevalue of the fragility changes from 168.963 to 22.976 when the mismatch changesfrom 0.023 to 0.25. It is shown that the fragility parameter is sensitive to theatomic size mismatch. The calculated pair distribution functions and mean squaredisplacements indicate that the glass-forming ability increases with the atomic sizemismatch.