| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Glasses and Optical Materials: Current Issues and Functional Applications
|
| Presentation Title |
Structural Relaxation Mechanism of Anisotropic Alkali Metaphosphate Glass |
| Author(s) |
Jun Endo, Seiji Inaba, Setsuro Ito |
| On-Site Speaker (Planned) |
Jun Endo |
| Abstract Scope |
To clarify the relaxation mechanism of the anisotropic glass of 12.5Li2O–12.5Na2O–12.5K2O–12.5Cs2O–50P2O5 (mol%), the change in storage modulus (Eˊ) and structure for isotropic (IG) and anisotropic (AG) glasses was investigated in the range from room temperature to above Tg. Although the Eˊ for IG monotonically decreased with increasing temperature up to Tg, the Eˊ for AG markedly dropped even below Tg and then increased to the value for IG. Raman spectra for AG showed that rapid weakening of the bond strength between alkali cations and non-bridging oxygens of some local structures in oriented chains occurred below Tg. Furthermore, the number of the local structures for AG increased with increasing temperature. These results suggest that the relaxation for AG was caused by the partial loss of cross-linking between the oriented chains below Tg and a disordering of the oriented chains due to loss of many cross-linking above Tg. |