Network structure and dynamics heterogeneities in Al2O3 system: insight from visualization and analysis of molecular dynamics data

Abstract

In this paper, structural properties, dynamical heterogeneity (DH) and diffusion mechanism in liquid alumina were investigated by molecular dynamic simulation. Structural characteristics were clarified through the pair radial distribution function, the distribution of AlOx coordination units and network structure. Furthermore, the diffusion mechanism was due to the transition of the structural units: AlOx → AlOx±1 and OAlx → OAlx±1. In particular, we have analysed the link-cluster function Flk(r, t) to clarify DH phenomena. The Flk(r, t) for sets of random, immobile and mobile atoms was quite different; the liquid Al2O3 exhibited DH at low temperature. We found the existence of separate fast and slow regions where the mobility of atom was extremely low or high, which was the main characteristic of DH.