Raman, FTIR, thermal and optical properties of TeO2-Nb2O5-B2O3-V2O5 quaternary glass system

A series of quaternary glass systems with the composition 79TeO2-(20−x)Nb2O5-xB2O3-1V2O5 was prepared using the melt quench technique. Such studies as optical absorption, Raman, FTIR spectroscopy, EPR and DSC were carried out on the glass system. The physical properties, such as density (ρ) and molar volume (VM), were determined. The Urbach energy (ΔE), optical band gap (Eopt), optical basicity (Λ), refractive index (n) and electron polarizability (α) of the glasses were determined from optical absorption data. Spin-Hamiltonian parameters of VO2+ ions were calculated from the EPR data. With the gradual substitution of B2O3 at the expense of Nb2O5, the density and optical band gap of the glasses decreased, and the electronic polarizability increased. EPR spectra revealed that VO2+ occupies an octahedral site with tetrahedral compression. Spin-Hamiltonian parameters g|| and g⊥ increased as B2O3 content increased in the glass. The glass transition temperature (Tg) also decreased as the B2O3 content in the glass increased.