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Tellurite And Fluorotellurite Glasses For Active And Passive

Tellurite And Fluorotellurite Glasses For Active And Passive

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5. Crystallisation studies; MDO 154<br />

The trace does not contain any clearly discernable crystalline peaks. However the<br />

amorphous halo is higher in intensity, and has developed a shoulder of lower intensity at<br />

around 23° 2θ.<br />

5.3. Discussion<br />

5.3.1. XRD<br />

5.3.1.1. XRD of batch materials<br />

TeO2<br />

Fig. (5.3) shows an XRD trace of the TeO2 used in this study, sourced from Alfa Aesar.<br />

The powder was shown to be phase pure (α-TeO2, tetragonal, space group P43212), in<br />

accordance with the stated high grade (Puratronic, 99.9995%). α-TeO2 or paratellurite,<br />

consists of a tellurium atom four coordinated to oxygen, with the tellurium lone pair of<br />

electrons occupying the oxygen free corner of the trigonal bipyramid (tbp). Chapter 2<br />

discusses the structures of TeO2 in more detail.<br />

ZnO<br />

Fig. (5.4) shows an XRD trace of the ZnO powder used in this study, sourced from Alfa<br />

Aesar. Again, the powder was shown to be phase pure as suggested by the stated grade

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