The structural transition under compression and correlation between structural and dynamical heterogeneity for liquid Al2O3

Abstract

This study reported a simulation of structural transition and correlation between structural and dynamical heterogeneity (DH) for liquid Al2O3. Structural characteristics of liquid Al2O3 were clarified through the pair radial distribution functions, the distribution of [Formula: see text] and [Formula: see text] ([Formula: see text], 4, 5, 6; [Formula: see text], 2, 3) basic structural units, angle and bond length distribution and 3D visualization. Simulation results revealed that network structure of liquid Al2O3 is built mainly by AlO3, AlO4, AlO5 and AlO6 units that are linked to each other through common oxygen atoms. We found the existence of separate AlO4-, AlO5- and AlO6-phases where the mobility of atoms can be determined. The atoms in AlO4-phase are more mobile than the ones in AlO5- and AlO6-phases. The existence of separate phases is evidence of DH in liquid Al2O3. Moreover, the self-diffusion of Al and O atoms was also discussed via characteristics of separate AlO4-, AlO5- and AlO6-phases.