Unique Sodium Phosphosilicate Glasses Designed Through Extended Topological Constraint Theory

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• 作者：Huidan Zeng ; Qi Jiang ; Zhao Liu ; Xiang Li ; Jing Ren ; Guorong Chen ; Fude Liu ; Shou Peng
• 刊名：Journal of Physical Chemistry B
• 出版年：2014
• 出版时间：May 15, 2014
• 年：2014
• 卷：118
• 期：19
• 页码：5177-5183
• 全文大小：376K
• 年卷期：v.118,no.19(May 15, 2014)
• ISSN：1520-5207

文摘

Sodium phosphosilicate glasses exhibit unique properties with mixed network formers, and have various potential applications. However, proper understanding on the network structures and property-oriented methodology based on compositional changes are lacking. In this study, we have developed an extended topological constraint theory and applied it successfully to analyze the composition dependence of glass transition temperature (T_g) and hardness of sodium phosphosilicate glasses. It was found that the hardness and T_g of glasses do not always increase with the content of SiO₂, and there exist maximum hardness and T_g at a certain content of SiO₂. In particular, a unique glass (20Na₂O鈥?7SiO₂鈥?3P₂O₅) exhibits a low glass transition temperature (589 K) but still has relatively high hardness (4.42 GPa) mainly due to the high fraction of highly coordinated network former Si⁽⁶⁾. Because of its convenient forming and manufacturing, such kind of phosphosilicate glasses has a lot of valuable applications in optical fibers, optical amplifiers, biomaterials, and fuel cells. Also, such methodology can be applied to other types of phosphosilicate glasses with similar structures.