LOCAL STRUCTURE AND DYNAMICS PROPERTY OF LIQUID Li2O.xSiO2

Abstract

The Li₂O-SiO₂ system composing of 3000 atoms has been constructed by molecular dynamics simulation. Three models with different density and concentration are prepared and analyzed in terms of radial distribution function, coordination number, distance and bond angle. The simulation reveals that despite the significant difference in density and chemical composition, the basic structural units of considered models including SiO₄, LiO₄, LiO₅, and LiO₆ are identical. The network structure is combined two separated phases silicon oxide and complex lithium oxide. When increasing Li₂O concentration, Lithium atoms tend to diffuse into free volume which located in tetrahedral SiO₄. The diffusion coefficient of Lithium increases nonlinearly with increasing concentration at the temperature of 3000 K.