| About this Abstract |
| Meeting |
MS&T23: Materials Science & Technology
|
| Symposium
|
Late News Poster Session
|
| Presentation Title |
D-24: Structural Rearrangements during Relaxation of Lithium Disilicate Glass |
| Author(s) |
Ricardo Felipe Lancelotti, Sabyasachi Sen, Edgar Dutra Zanotto |
| On-Site Speaker (Planned) |
Ricardo Felipe Lancelotti |
| Abstract Scope |
Glasses are thermodynamically unstable materials that spontaneously relax toward the supercooled liquid state. Although the kinetics of the relaxation process can be obtained by tracking a property variation, the experimental determination of the atomic-scale structural rearrangements by which a glass relaxes remains elusive. We investigated the short-range order structural rearrangements that take place during relaxation in lithium disilicate using Raman and Nuclear Magnetic Resonance techniques. The results indicate that the structural relaxation of this glass involves the Q-species disproportion reaction Q2 + Q4 → 2Q3, which shifts to the right upon lowering of temperature or fictive temperature. The concomitant rearrangement of the network, in addition to the changes in the local environment of the lithium ions reported in a recent study in the literature, can be shown to be consistent with the lowering of the ionic conductivity and eventually the nucleation of Li2Si2O5 crystals upon prolonged annealing of the glass. |