| About this Abstract |
| Meeting |
MS&T23: Materials Science & Technology
|
| Symposium
|
Glasses and Optical Materials: Current Issues and Functional Applications
|
| Presentation Title |
The Influence of Divalent Cations on the Network Structures and Properties of Phosphate and Aluminophosphate Glasses |
| Author(s) |
Charmayne E. Lonergan, Richard Brow |
| On-Site Speaker (Planned) |
Charmayne E. Lonergan |
| Abstract Scope |
The coordination requirements of divalent cations (R2+) affect the structures and properties of phosphate and aluminophosphate glasses. Hoppe has shown, for example, that in binary RO-P2O5 glasses, R2+ ions are initially incorporated as isolated polyhedra that link neighboring P-tetrahedra through their nonbridging oxygens (NBO) and that the average coordination number of those R2+ ions decrease to a minimum size with increasing RO-content to avoid the formation of an R2+-NBO-R2+ subnetwork. In this paper, we will use this model to explain the influence of divalent oxides like MgO, ZnO, and SnO on the properties of phosphate and aluminophosphate glasses and will show that changes in Sn2+ and Al3+ coordination numbers and the trends in thermal and mechanical properties can be explained by the interplay between the phosphate network and the divalent cation subnetwork that constitute the structures of these glasses. |