Influence of the borate anomaly on the Sn(II) environment in tin borate glasses
UNSPECIFIED (2003) Influence of the borate anomaly on the Sn(II) environment in tin borate glasses. In: 4th International Conference on Borates Glasses, Crystals and Melts, 2002, CEDAR RAPIDS, IOWA.Full text not available from this repository.
B-11 and Sn-119 nuclear magnetic resonance (NMR) spectroscopies have been used to determine the local environments of boron and tin in binary tin borate glasses of general composition xSn O. (1 -x) B2O3 (0.2less than or equal toxless than or equal to0.7). The changes in NMR parameters with composition have been correlated with the 'so-called' anomalies in the thermophysical properties of the glasses. The variation in glass density with x shows a change in slope and the glass transition temperature goes through a maximum at x=0.5 which is where B-4 (=[BO4]/B-total) also goes through a maximum. This is reminiscent of other binary systems although the deviation from the simple x/(1-x) law occurs earlier than in alkali borate systems; the maximum in B-4 is at higher x; and the value of this maximum is 0-32, somewhat lower than usually observed. The B-11 MAS NMR spectra have been fitted to three species (B-4, B-3S and B-3A). The maximum in B-4 is accompanied by discontinuities in B-3A and B-3, The quadrupole parameters for the B-3 species also show discontinuities at a value of x=0.5. Static Sn-119 NMR spectra were fitted to yield values for the principal components (d(11), d(22), d(33)) of the chemical shift tensor All these components initially increased in a near linear fashion with x but the slope decreased by a factor of similar to4 beyond x=0.5. These observations have been interpreted in terms of change in the type and fractions of species present.
|Item Type:||Conference Item (UNSPECIFIED)|
|Subjects:||Q Science > QD Chemistry
T Technology > TP Chemical technology
|Journal or Publication Title:||PHYSICS AND CHEMISTRY OF GLASSES|
|Publisher:||SOC GLASS TECHNOLOGY|
|Number of Pages:||5|
|Page Range:||pp. 59-63|
|Title of Event:||4th International Conference on Borates Glasses, Crystals and Melts|
|Location of Event:||CEDAR RAPIDS, IOWA|
|Date(s) of Event:||2002|
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