Tellurite And Fluorotellurite Glasses For Active And Passive

3. Glass batching and melting; MDO 72
Table (3.4): Summary of batch calculation above for 10g of glass MOF001 (65TeO2-
10Na2O-25ZnF2 mol. %).
Compound
in glass
RAM /
-1
g.mol
Batch as
RAM /
-1
g.mol
Ratio Mol. % Wt. % Mass / g
TeO2 159.60 TeO2 159.60 1.00 65 76.40 7.64
Na2O 61.98 Na2CO3 105.99 1.71 10 4.57 0.78
ZnF2 103.37 ZnF2 103.37 1.00 25 19.03 1.90
Total: 100 100.00 10.32
Glasses were batched into a gold or platinum crucible on electronic scales (Sartorius
BP211D), which nominally read to five decimal places (i.e. to the nearest 1×10 -5 g).
The chemicals were weighed out accurately to three decimal places (i.e. to the nearest
1×10 -3 g or 1 mg) from the batch calculation using clean stainless steel spatulas
(Fisher), washed with acetone (Fisher analytical reagent grade) before batching and
cleaned with non-shedding tissues (Fisher) between batching each chemical. The
amount of glass batched depended on the use of the final glass; for instance in order to
carry out thermal analysis and optical spectroscopy, typically just over 10g of material
was batched yielding around 10g of final glass (see Table (3.4)). In order to produce
an unstructured glass preform for fibre-drawing, typically just over 30g of material
was batched yielding around 30g of final glass.
3.3. Glass Melting
Glasses were melted in a resistance furnace (Instron TF105/4.5/1ZF using an Instron
C130011100 power supply containing a Eurotherm 2408 controller) housed in a
stainless steel lined fume cupboard in a lidded platinum or gold crucible (height = 40
mm, base diameter = 23 mm, top diameter = 40 mm). The crucibles were cleaned by
soaking in Fisher 48% HCl acid, diluted to 3M with distilled water, between each