Tellurite And Fluorotellurite Glasses For Active And Passive

4. Thermal properties and glass stability; MDO 99
Heat Flow / mW
0
-10
-20
-30
-40
% Transformed
Crystallisation Peak
50% peak area
−> 0.145 min.
−> 8.7 sec.
Time / sec.
0 2 4 6 8 10 12
100
-50
0
0.00 0.05 0.10 0.15 0.20
Time / min.
Fig. (4.9): Method of obtaining time values for TTT plot for isothermal hold of glass
MOF005 (70TeO2-10Na2O-20ZnF2 mol. %) at 325°C.
Time of the onset of crystallisation was also used to plot TTT diagrams, which is a more
conservative estimate of the kinetics of devitrification.
80
60
40
20
% Transformed