Tellurite And Fluorotellurite Glasses For Active And Passive

5. Crystallisation studies; MDO 152
Despite the presence of a noisy background signal, probably due to an amorphous
component to the sample, peaks were matched to: JCPDS card number 44-0241, dizinc
tritellurium oxide Zn2Te3O8, monoclinic, space group C2/c; and 81-0954, sodium zinc
fluoride NaZnF3, orthorhombic, space group Pbnm. Table (5.9) shows the ten most
intense peaks with corresponding 2θ (observed and theoretical), phases and Miller
indices.
Table (5.9): Ten most intense peaks with corresponding 2θ (observed and theoretical) and
Miller indices for glass MOF005 (70TeO2-10Na2O-20ZnF2, mol. %) which crystallised at
400°C in TMA, at a heating rate of 10°C.min. -1 , under a helium atmosphere, with an
applied load of 250 mN..
Observed
2θθθθ / °
Observed
intensity / %
Theoretical
2θθθθ / °
Theoretical
intensity / %
Phase hkl
JCPDS
Card
18.54678 44.8 18.50869 31 Zn2Te3O8 110 44-0241
19.63449 32.2 19.56929 8 Zn2Te3O8 11 1 "
22.63353 41.0 22.58055 23 Zn2Te3O8 202 "
22.97567 44.8 22.89715 100 NaZnF3 110 / 002 81-0954
27.58675 100.0 27.52083 26 Zn2Te3O8 31 1 44-0241
29.47867 57.9 29.70982 3 Zn2Te3O8 31 2 "
30.60927 77.0 30.56920 100 Zn2Te3O8 113 "
31.79723 33.9 31.72810 22 Zn2Te3O8 20 4 "
32.63209 29.5 32.59806 78 NaZnF3 112 81-0954
57.36503 29.0 57.34960 25 Zn2Te3O8 42 5 44-0241
5.2.1.4. Heat treated Er +3 -doped compositions
Glass MOF017 (69.86TeO2-9.98Na2O-19.96ZnF2-0.2ErF3 mol. %) was heat treated to
attempt to grow Er +3 -rich nano-crystals. Fig. (5.12) shows an XRD trace of the glass
before any heat treatment.