Topological Origin of the Network Dilation Anomaly in Ion-Exchanged Glasses

Although ion exchange is commonly used to strengthen oxide glasses, the products usually reach just a small fraction of their maximum theoretical strength, due to the so-called atomic network dilation anomaly. Based on molecular dynamics simulations, this study reveals that the dilation anomaly is topological in origin. Surprisingly, glasses exhibiting an optimal (isostatic) atomic topology are found to be free of this anomaly. These results establish topological nanoengineering as a promising route to designing ultrastrong glasses, with significant implications for industry---and your next mobile phone.