Abstract
The glasses with composition 75 TeO2-5 WO3-15 Nb2O5–5NiO, 78 TeO2-5 WO3-15 Nb2O5–2NiO and 78 TeO2-5 WO3-15 Nb2O5–2NiCl in mol% prepared by using a conventional melt-quench technique. Thermal stability (ΔT), glass transition temperature (Tg) of prepared glasses were determined by using DTA technique. It was noticed this glasses have highest value of glass transition temperature, Tg, in the range from 423 to 414°C. Raman spectroscopic studies showed that the glass network consists of TeO4, TeO3+1, TeO3, WO4, WO6 and NbO6 units as basic structural units. The ratio of TeO3/TeO4 was determined as a measurement of the non-bridging oxygen/bridging oxygen bonds in the network structure. Transmittance and absorbance were measured by a spectrophotometer in the spectral range of 190–2500nm. Some optical properties such as the optical band gap (Eopt), absorption coefficient(α), refractive index (n) and the cut off in UV and IR bands to the bandpass filter were calculated from the absorbance and transmittance, which confirmed the optical properties of this type of filter.