Abstract and subjects
The effect of Sr modifier atoms on the structure of stannosilicate glasses of composition (Sr0)
x
(SnO)
0.5−
x
(SiO
2)
0.5, with 0
⩽
x ⩽
0.15, has been studied using Mössbauer spectroscopy and neutron and X-ray diffraction. The tin is mostly in the Sn
2+ state. The Sr–O bond length undergoes a step decrease from (2.640
±
0.005) Å to (2.585
±
0.005) Å as
x increases from 0.10 to 0.15, indicating a decrease in co-ordination number from 8 to 7. A Sn–Sn distance of 3.507
±
0.005
Å is revealed by a first-order difference calculation from the
x
=
0 sample. This is too short to be consistent with significant edge sharing of [SnO
3] trigonal pyramids.