Optical, thermal and electrical properties of ternary TeO2–WO3–PbO glasses

Optical absorption, MDSC and DC conductivity studies have been used to study the influence of WO3 and PbO oxides on optical, thermal and conductivity properties of the TeO2–WO3–PbO glass system. From MDSC thermogram, the glass transition temperature (Tg), onset crystallization (To), thermal stability (ΔT), glass transition width (ΔTg), heat capacities in the glassy and liquid state (Cpg and Cpl), heat capacity change (ΔCp) and ratios Cpl/Cpg of the glass systems were calculated. The variation in Tg with the addition of PbO content has been correlated with structural properties ( n c ¯ , nb, F ¯ ). The optical band gap (Eopt), Urbach energy (ΔE), molar refraction (RM), metallization criterion (M), optical basicity (Λ), electronic polarizability of the oxide ion ( α O 2 - ) and refractive index (n) have been determined from optical absorption data and their variations have been discussed in terms of the glass structure. DC electrical conductivity of the present glasses was studied in the temperature range of 150 °C to below their Tg values. The activation energies (Eact) of all the glasses for the conduction were calculated and found to be composition dependent.