10.06.2013 Views

Tellurite And Fluorotellurite Glasses For Active And Passive

Tellurite And Fluorotellurite Glasses For Active And Passive

Tellurite And Fluorotellurite Glasses For Active And Passive

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

4. Thermal properties and glass stability; MDO 111<br />

It can be seen the glasses containing Er2O3 (0.1 and 1 mol. %) and higher levels of ErF3<br />

(0.2 mol. %) were relatively unstable, exhibiting multiple crystallisation exotherms, with<br />

Tx-Tg values ≈ 50°C for MOF017. However, incorporating an order of magnitude lower<br />

dopant level of the fluoride (0.02 mol. %) resulted in high stability glass, with a Tx-Tg<br />

value (≈ 160°C) similar to the parent glass, MOF005 (70TeO2-10Na2O-20ZnF2).<br />

Effect of melting time for glass 70TeO2-10Na2O-20ZnF2 mol. %<br />

Fig. (4.20) shows the variation in DTA trace with increasing melting time for samples<br />

taken from glass preforms MOF005vi, vii and viii which were all 70TeO2-10Na2O-<br />

20ZnF2 mol. %.<br />

<br />

−><br />

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!