Thermal, structural and optical properties of new tungsten lead–pyrophosphate glasses

Crystalline lead–pyrophosphate precursor was prepared in aqueous solution from lead nitrate and phosphoric acid and characterized by X-ray diffraction, thermogravimetry and Raman scattering. This crystalline lead–phosphate was then used to prepare glass samples in the binary system Pb2P2O7–WO3. Dependence of WO3 content on thermal, structural and optical properties were investigated by thermal analysis (DSC), Raman spectroscopy, UV–visible and near-infrared absorption and M-Line technique to access refractive index values. Incorporation of WO3 in the lead–pyrophosphate matrix enhances the glass transition temperature and thermal stability against devitrification, favors formation of POW bonds and WO6 clusters. In addition, optical properties are strongly modified with a redshift of the optical bandgap with WO3 incorporation as well as an increase of the refractive index from 1.89 to 2.05 in the visible.

► New stable glasses was synthesized and characterized in Pb2P2O7–WO3 binary system.
► These glasses have high thermal stability and refractive index.
► Good candidates for optical fiber fabrication and for non-linear optical studies.