The influence of TiO2 on structural, physical and optical properties of B2O3 –TeO2 – Na2O – CaO glasses

Abstract

B2O3 –TeO2 – Na2O – CaO glasses doped with small concentrations of TiO2, from 0.5 to 3 mol%, were prepared by traditional technique. The changes in the structure of studied glasses were observed by using FTIR technique and it was found that glasses containing different structure units of borate and tellurite groups. The change in the many optical and physical parameters such as density, molar volume, band gap, optical backing density, refractive index and others were studied. The density was found to increase with the addition of TiO2 till 1 mol% then begin to decrease and the opposite trend was observed to molar volume. Energy band gap was measured by two techniques ASF and Tauc's models and their values was very close to each other and to decrease with the addition of TiO2. The refractive index was found to increase with the addition of TiO2 from 2.4 for base glass to 2.59 for glass containing 3 mol% of TiO2. The ionic concentration of Ti, the interionic distance ri, field strength F, dielectric constant, molar refraction index rm, molar polarizability, average electronegativity, and the reflection loss (rL) were rise with increasing TiO2 content. On the other hand, there are some properties such as transmission coefficient (T) was found to decrease with increasing the concentration of Ti ions.