Title : Quantitative Analysis of the Thermal Properties of TeO2-Nb2O5-TiO2 Glasses
Glasses of the system ( 95-x) TeO2+5Nb2O5+xTiO2 (where x=2.5 to 12.5 mol% with an interval of 2.5 mol%) have been successfully prepared via conventional melt quench technique. Density and molar volume have measured for the present glasses. Differential thermal analysis (DTA) traces for the prepared glass with systematic heating rate 10 0C/min have been carried out. The glass transition temperature Tg, onset crystallization temperature Tc, melting temperature Tm , glass stability range S, glass factor Kg (Hurby parameter) and fragility of the present glasses have been recorded and calculated for every glass composition. The compositional dependences of the Tg, Tm, Tc, S, Kg and fragility have been discussed and correlated to the structure of tested glasses. It is found that the gradual replacement of oxides, TiO2 by TeO2, increases the glass transition temperature and decreases the fragility of the glasses. Quantitative analysis of the above thermal properties of the present glass systems with the structure parameters like average cross-link density, number of bonds per unit volume and average stretching force constant have been studied for every glass composition.