About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Glasses and Optical Materials: Challenges, Advances, and Applications
|
| Presentation Title |
Structure-Property Correlations in the Bi2O3-ZnO-B2O3 Pyroborate Glass System and the Effects of Crucible Dissolution |
| Author(s) |
Lenorah Haight-Stott, Nagia Tagiara, Henrik Bradtmüller, Efstratios Kamitsos, Doris Möncke |
| On-Site Speaker (Planned) |
Lenorah Haight-Stott |
| Abstract Scope |
Glasses of the compositional series 6xZnO-(2-2x)Bi2O3-3B2O3 (0 ≤ x ≤ 1) were prepared by the conventional melt-quench technique using either alumina or platinum-gold crucibles. Despite keeping the oxygen to boron ratio at a constant value of 2.5 - nominally expecting pyroborate units only as borate species – significant structural variations were observed by infrared (IR), Raman and 11B and 27Al NMR spectroscopy. Structural changes were correlated with thermal and optical properties including density, calculated refractive index, and glass transition temperature (Tg). Varying the conditional modifiers Zn2+ versus Bi3+ influences speciation of borate units; the borate network under-modified in bismuth-rich glasses while zinc-rich glasses are characterized by disproportionation of pyroborate into orthoborate and metaborate units. 27Al NMR revealed the presence of [AlO4]- tetrahedra due to crucible dissolution and consequently changes in borate speciation. |