Atomic structure and modifiers clustering in silicate glasses: Effect of modifier cations
Published in arXiv, 2020
Abstract
Oxide glasses are made of a network of glass former polyhedra, and modifiers which have a role in neutralizing the charge of the glass former polyhedra or depolymerize the glass network. The effect of the modifier content on the structure and properties of the glass are to some extent, well known. However, the effect of the type of modifiers on the clustering and the tendency to form a phase separation in the glass is not investigated in detail and still not fully understood until now. Here, we use molecular dynamics to investigate the effect of the modifier type on the structure and the clustering tendency of a series of modified silicate glasses. Specifically, we show that the tendency of modifier–modifier cluster formation is linked to the modifier size and modifier–oxygen bond strength. The effect of different modifiers on the short- and medium-range structure of the glass is also discussed. This allows us to get an overview of the effect of cations nature on the properties of the glass and opens a new window for further development and optimization of the glass properties.
Achraf Atila. "Atomic structure and modifiers clustering in silicate glasses: Effect of modifier cations." arXiv preprint arXiv:2007.09247 (2020).
Plain Language Summary
🇬🇧 English
Oxide glasses are built from a rigid network of glass-former polyhedra together with 'modifier' cations that either balance charge or break up the network. While the influence of how much modifier is added is fairly well understood, the effect of which modifier is used on how those cations cluster together — and on the glass's tendency to phase-separate — has been far less clear. Using molecular dynamics simulations, this study compares a series of silicate glasses containing different modifier cations and shows that the tendency of modifiers to cluster with one another is controlled by the size of the modifier cation and the strength of the modifier–oxygen bond. The work also traces how different modifiers reshape the glass at the short and medium range, giving a clearer picture of how the choice of cation can be used to develop and optimize glass properties.