Journal
JOURNAL OF NON-CRYSTALLINE SOLIDS
Volume 381, Issue -, Pages 23-28Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.jnoncrysol.2013.09.018
Keywords
Sub-T-g annealing; Enthalpy relaxation; Structural ordering; Structural heterogeneity; Crystallization
Funding
- Danish Research Council [09-064216]
- Taishan Scholar Fund of Shandong Province, China
Ask authors/readers for more resources
We study the sub-T-g relaxation in an extremely unstable glass former, i.e., 65SiO(2)-35Al(2)O(3), and its relation to structural heterogeneity (e.g., structurally ordered domains in glass matrix). This is done by hyperquenching (similar to 10(6) K/s) the liquid, then annealing the hyperquenched (HQ) glass below T-g and subsequently scanning the annealed HQ glass in a differential scanning calorimeter (DSC). The results show that structural ordering can take place even below T-g. An endothermic pre-peak is observed when the HQ sample is annealed at 0.75T(g) for sufficiently long time, which is, however, much weaker compared to that of stable glass formers subjected to same annealing conditions. We also investigate the effect of the sub-T-g annealing on crystallization above T-g. The results imply that some structurally ordered domains exist already in the liquid state. The ordered domains lower the activation energy for further structural ordering during the sub-T-g annealing, and thereby lowers the activation energy for crystal growth above T-g. (C) 2013 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available