Effect of Tungsten Oxide on Structure and Physical Properties for Germanium Boro-silicate glass

This research was studied the effect of adding tungsten oxide (WO 3 ) on the structural and physical properties of the germanium boro-silicate (Na 2 B 4 O 7 -SiO 2 -Ge 2 O 3 ) glass. The role of tungsten oxide in a glass matrix was studied by using infrared spectra, optical absorption and density. The optical band gap and Urbach energy were determined based on the absorption spectra. The infrared spectra and UV–vis spectroscopy results show that, the used glasses have glassy or amorphously structure and its increase with increasing WO 3 content. The density of Na 2 B 4 O 7 -SiO 2 -(Ge 2 O 3 ) 15−x -(WO 3 ) x (x = 0, 2, 4, 6 and 8 wt. %) glasses increased in the range of 2.574 to 2.683 g/cm 3 with the increasing tungsten oxide content. The optical band gap value decreased, from 3.34 to 2.81 eV, but Urbach energy increased with increasing WO 3 concentration.