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Chalcogenide Glasses 59
20.0
4.14
18.0
16.0
14.0
12.0
10.0
8.0
4π r 2 ρ 0 – 4π r 2 ρ 4.0 2.62
6.0
2.0
0.0
–2.0
–4.0
–6.0
–8.0
–10.0
–12.0
–14.0
0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2 5.6 6.0
R (Å)
FIGURE 2.21 Radial distribution function of SiTe glass.
4
Ge-Te glasses. The X-ray results did not support the existence of Si-Te
4
tetrahedral molecules which one would expect to be present.
2.6.5 Conclusions from the TI Exploratory Programs
of 1962 to 1965
1. Seven ternary IVA-VA-VIA glass forming systems were inves-
tigated in this study. The Si-As-Te, the Ge-As-Te, and the Ge-
P-Te glass systems showed the best infrared transmission in
the 8- to 14-µm region. Attempts to form glasses using Sn or
containing B failed. Silicon formed an unstable bond with
selenium with a tendency to react with water to form hydro-
gen selenide. Glasses containing four elements were formed
by combining the Si-As-Te glasses with the Ge-As-Te glasses.
2. The chemical bonding and thus the properties change with
compositions within the glass forming region. The extent of
