Influence of Sb2O3 on tellurite based glasses for photonic applications

Abstract

Tellurite based ternary glasses with compositions TSW: 75TeO2–xSb2O3–(25−x)WO3 where x = 5, 10, 15, 20 mol% were prepared by conventional melt quenching and pressing method. The prepared samples were investigated by X-ray diffraction (XRD), Differential thermal analysis (DTA), UV-VIS absorption spectroscopy, Raman and Fourier transform-infrared (FTIR) spectroscopies. XRD patterns recorded at room temperature confirm the amorphous nature of the glasses. Thermal properties such as glass transition temperature (Tg) and thermal stability of the glasses were determined from the differential thermal analysis curves. The absorption edge of the glasses shifts towards lower wavelength with increasing antimony oxide content in the glass indicating the increase of rigidity of the glass. FTIR and Raman spectra of the glasses showed the existence of WO4, WO6, TeO4, TeO3, TeO3+1 and SbO3 structural units in the glass network. The gradual increase of antimony oxide content in the glass matrix causes the transformation of TeO4 structural units to TeO3 or TeO3+1. Energy band gaps (Eg) and Urbach energies (ΔE) of the glasses were obtained by using the optical absorption spectral data. Density, molar volume, oxygen molar volume and oxygen packing density (OPD) of the glass samples were calculated to evaluate the physical and structural properties of the glasses.