Modifier coordination and phosphate glass networks
The addition of up to ∼16 mol% Cs 2O to vitreous P 2O 5 reduces the glass transition temperature ( T g) by 150 K, whereas further additions up to 60 mol% increases T g by ∼20 K. 31P magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra indicate that the phosphate network is progressive...
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Published in | Journal of non-crystalline solids Vol. 274; no. 1; pp. 9 - 16 |
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Main Authors | , , |
Format | Journal Article Conference Proceeding |
Language | English |
Published |
Amsterdam
Elsevier B.V
2000
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | The addition of up to ∼16 mol% Cs
2O to vitreous P
2O
5 reduces the glass transition temperature (
T
g) by 150 K, whereas further additions up to 60 mol% increases
T
g by ∼20 K.
31P magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra indicate that the phosphate network is progressively depolymerized over the entire range of compositions. The property trend is explained by a transition in the Cs
+ coordination environment, from isolated Cs-polyhedra below ∼16 mol% Cs
2O to a corner-sharing Cs-polyhedral sub-structure in the glasses with greater Cs
2O contents. This ‘modifier transition’ does not occur in Al phosphate glasses.
27Al MAS NMR spectra indicate that the average Al coordination number decreases with increasing Al
2O
3 content to avoid the formation of Al–O–Al bonds in these binary phosphate glasses. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0022-3093 1873-4812 |
DOI: | 10.1016/S0022-3093(00)00178-2 |