DYNAMIC MECHANISM OF LIQUID–GLASS TRANSITION FOR Mg7Zn3 ALLOY

Abstract

The dynamic mechanism of liquid–glass transition for Mg 7 Zn 3 alloy is studied by the molecular dynamics simulations. The temperature dependences of dynamic properties during the liquid–glass transition are investigated. Two relaxation processes are clearly observed near the glass transition temperature. The diffusivity deviates from the Arrhenius law after the melting temperature Tm and satisfies the power law before the dynamic singularity temperature Tc owing to the cage effect. The solid- and liquid-like atoms are defined according to the vibration characteristic of atoms. It is found that the solid-like atoms have higher local packing density, lower mobility and potential energy than the liquid-like ones. Based on the evolutions of solid- and liquid-like atoms, the atomic mechanism of dynamic liquid–glass transition is systematically elucidated, which is consistent with the potential energy landscape.