Crystallisation kinetics of the erbium doped soda-tellurite glasses were studied using the differential thermal analysis (DTA) and differential scanning calorimetery (DSC) techniques. The DTA curves in the temperature range of 350 K to 650 K were obtained from isochronal heating rates, chosen in the range of 2 to 20 K/min. DSC isothermal curves were used to calculate the fraction of crystals formed on reheating. The apparent activation energies for devitrif1cation were derived by mεasuring the shifts in thε values of Tg and Tx with heating rates, using the Kissinger method. The derived values of apparent activation energies for isochronal and isothermal methods varied in the range of 190-204 ± 5 kJ mor1. The X-ray powder diffraction analysis of heat treated and transparent samples showed the presence of nano-scale size sodium-tellurite crystals. These crystallites were found to have a strong influence on the full width of half maxima of the transition in Er3+:4I13/2 -> 4I15/2, which extended from 70 nm in the vitreous materials to 132 nm in glass-ceramic materials.
1. Introduction
2. Experimental
3. Results and Discussions:
4. Conclusions
Acknowledgements
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