Effect of K2O on the crystallization mechanism of SiO2-Li2O glass analyzed by molecular dynamic simulation

The molecular dynamics method is used to analyze the effect of K2O on crystallization of SiO2-Li2O glass. The dependence of Q(n) (Number of bridging oxygens connected to a silicon atom in the network) on temperature was calculated, which was used to analyze the crystallization behavior of three glasses combined with their XRD results. The relationship between Q(n) and crystalline phases was finally established. When Q(3) > Q(2) and Q(4) is high, LD is the only crystalline phase at both low and high temperature (with a cutoff point of 973 K). When Q(3) > Q(2) and Q(4) is low, LMS is a major crystalline phase and LD is a minor crystalline phase at low temperature, but LD is a major crystalline phase and LMS is a minor crystalline phase at high temperature. When Q(3) approximate to Q(2) and Q(4) is low, LMS is the only crystalline phase at both low and high temperature.