Diffusion Mechanisms in Lithium Disilicate Melt by Molecular Dynamics Simulation

TL;DR

This study uses molecular dynamics simulations to analyze diffusion mechanisms in lithium disilicate melt, revealing agreement with experiments, adherence to the Stokes-Einstein relation at certain temperatures, and the presence of dynamical heterogeneities.

Contribution

The paper demonstrates the effectiveness of molecular dynamics in capturing atomic diffusion and reveals temperature-dependent diffusion behaviors in lithium disilicate melt.

Findings

Diffusion coefficients match experimental data.

System obeys Stokes-Einstein relation down to 1400 K.

Dynamical heterogeneities are observed at certain conditions.

Abstract

In this work we study the diffusion mechanisms in lithium disilicate melt using molecular dynamics simulation, which has an edge over other simulation methods because it can track down actual atomic rearrangements in materials once a realistic interaction potential is applied. Our simulation results of diffusion coefficients show an excellent agreement with experiments. We also demonstrate that our system obeys the famous Stokes-Einstein relation at least down to 1400 K, while a decoupling between relaxation and viscosity takes place at a higher temperature. Additionally, an analysis on the dynamical behavior of slow-diffusing atoms reveals explicitly the presence of dynamical heterogeneities.