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 Qn (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 Qn and crystalline phases was finally established. When Q3 > Q2 and Q4 is high, LD is the only crystalline phase at both low and high temperature (with a cutoff point of 973 K). When Q3 > Q2 and Q4 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 Q3 ≈ Q2 and Q4 is low, LMS is the only crystalline phase at both low and high temperature. HIGHLIGHTSThe Qn of SiO2-Li2O glass and its variation with temperature were calculated by molecular dynamics simulation.The relationship between Qn and crystalline phases was established.The effect of K2O on crystallization of SiO2-Li2O glass was elucidated based on Qn.