2018 年 17 巻 3 号 p. 113-116
We investigated the structural units of xNa2O-(1 − x) B2O3 glasses using molecular dynamics (MD) simulation with the interatomic potential provided by first-principles calculations. The results are consistent with experimental trends in interatomic distance, linear thermal expansion coefficient and BO4 units. The amount of 5- to 8-membered rings at x = 0.2 is larger than the other composition range. This suggests that the structural unit constructed by a few rings is related to suppression of thermal expansion.