Atomistic simulation of silica-based glasses using molecular dynamics

Abstract

Silica based glasses are being utilized ubiquitously in different disciplines of everyday life. Addition of modifiers in silica based glasses varies their physical and chemical properties. In this dissertation the preparation of silica based ternary glasses SiO2- CaO-ZrO2 using molecular dynamic simulation has been done. The structures of different silica based glasses with compositions 70SiO2-(30-x)CaO-xZrO2 (x=0,5,10,15,20,25,30) were generated using MD simulations following melt quench method. Pedone‟s potential is used to meet the requirement of molecular dynamics simulations. The radial distribution function analysis suggests that the clustering of the silica tetrahedral glass network increases with the concentration of calcium. The different concentrations of CaO and ZrO2 noticeably change the glass transition temperature of different compositions of glasses. The structural analysis of our ternary glasses equips us with the information of oxygen-silicon coordination number and the Q n species found in the prepared glasses. The appearance of different ratios of Qn species in our glasses is because of the changing concentration of CaO and ZrO2 in the composition.