Abstract
Classical considerations of the stability of amorphous networks have sensibly concluded that a network should weaken when mechanical constraints are removed. In covalently-bonded glass networks, this weakening is evidenced by the "fragility" and, in many cases, the fragility increases as the density of covalent bonds decreases. However, covalent glasses that possess substantial intermediate range order (IRO) exhibit an increase of fragility with increasing bond density - a paradoxical weakening in spite of the addition of reinforcing constraints. Here we resolve this paradox by suggesting that such IRO-containing networks require a renormalization. A coarse-graining of IRO structural units is proposed that permits a network to effectively weaken despite increases in the overall density of bonds. Through this coarse-graining approach, we demonstrate the emergence of a universal dependence of fragility on network connectivity that is well obeyed by more than 75 distinct network-forming glasses including chalcogenides, borates, germanates, phosphates and aluminophosphates.
| Original language | English |
|---|---|
| Pages (from-to) | 16-20 |
| Number of pages | 5 |
| Journal | Journal of Non-Crystalline Solids |
| Volume | 402 |
| DOIs | |
| State | Published - Oct 15 2014 |
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All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Ceramics and Composites
- Electronic, Optical and Magnetic Materials
- Materials Chemistry
Cite this
Building up a weaker network : The effect of intermediate range glass structure on liquid fragility. / Sidebottom, David L.; Tran, T. D.; Schnell, S. E.
In: Journal of Non-Crystalline Solids, Vol. 402, 15.10.2014, p. 16-20.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Building up a weaker network
T2 - The effect of intermediate range glass structure on liquid fragility
AU - Sidebottom, David L.
AU - Tran, T. D.
AU - Schnell, S. E.
PY - 2014/10/15
Y1 - 2014/10/15
N2 - Classical considerations of the stability of amorphous networks have sensibly concluded that a network should weaken when mechanical constraints are removed. In covalently-bonded glass networks, this weakening is evidenced by the "fragility" and, in many cases, the fragility increases as the density of covalent bonds decreases. However, covalent glasses that possess substantial intermediate range order (IRO) exhibit an increase of fragility with increasing bond density - a paradoxical weakening in spite of the addition of reinforcing constraints. Here we resolve this paradox by suggesting that such IRO-containing networks require a renormalization. A coarse-graining of IRO structural units is proposed that permits a network to effectively weaken despite increases in the overall density of bonds. Through this coarse-graining approach, we demonstrate the emergence of a universal dependence of fragility on network connectivity that is well obeyed by more than 75 distinct network-forming glasses including chalcogenides, borates, germanates, phosphates and aluminophosphates.
AB - Classical considerations of the stability of amorphous networks have sensibly concluded that a network should weaken when mechanical constraints are removed. In covalently-bonded glass networks, this weakening is evidenced by the "fragility" and, in many cases, the fragility increases as the density of covalent bonds decreases. However, covalent glasses that possess substantial intermediate range order (IRO) exhibit an increase of fragility with increasing bond density - a paradoxical weakening in spite of the addition of reinforcing constraints. Here we resolve this paradox by suggesting that such IRO-containing networks require a renormalization. A coarse-graining of IRO structural units is proposed that permits a network to effectively weaken despite increases in the overall density of bonds. Through this coarse-graining approach, we demonstrate the emergence of a universal dependence of fragility on network connectivity that is well obeyed by more than 75 distinct network-forming glasses including chalcogenides, borates, germanates, phosphates and aluminophosphates.
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U2 - 10.1016/j.jnoncrysol.2014.05.010
DO - 10.1016/j.jnoncrysol.2014.05.010
M3 - Article
VL - 402
SP - 16
EP - 20
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
SN - 0022-3093
ER -