Regular Article

Microstructure of lead silicate melt under compression: insight from computer simulation

Hanoi University of Science and Technology, Hanoi, Vietnam

^a e-mail: hong.nguyenvan@hust.edu.vn

Received: 8 September 2019
Received in final form: 29 October 2019
Published online: 11 December 2019

Abstract

The microstructure of lead silicate melt (Pb₂SiO₄) and its change under high pressure are investigated by molecular dynamics simulation. The models are constructed at temperature of 3000 K and in the 0–50 GPa pressure range. The microstructural correlate of pair radial distribution functions is clarified. Short range order (SRO) and intermediate range order (IRO) are investigated via topology analysis of SiO_x units and SiO_x-clusters. Microstructural analysis, cluster-analysis and visualization techniques are applied to clarify the characteristics of -Si-O- network structure. The local environment around Pb⁺², Si⁺⁴ and O⁻² ions, incorporation mechanism of Pb²⁺ cations into -Si-O- network, the microphase separation under compression have been clarified. Specially, the storage mechanism of hazardous metal ions (heavy metal ions in industrial and nuclear wastes) in silica-based multicomponent oxide systems is also discussed in detail.