FTIR, EPR, and Optical Absorption Spectra of Vanadium Ions Doped in (B2O3–ZnO-Na2O) Glasses.

Glasses of the composition xV₂O₅–(100-x)[0.5B2O3-0.2ZnO0.3Na₂O], where x = 0, 0.5, 1, 2 and 3 mol% were prepared by melt quenching method. It can be seen that both density ρ and molar volume VM were found to almost increases by doping of V₂O₅. FTIR spectra in the frequency range (400-2000 cm-1 ) were measured for the prepared glasses. It can be seen that studied samples contain the bands characteristic for B2O3 [(δ (B-O-B)=715cm-1 , ρ (B-O) =1031cm-1 )], and V₂O₅ (ρ (V-O) = 945 cm -1 ) groups. From the FTIR studies, it was observed that the glasses are made up of BO3 and BO4 groups. The Electron Paramagnetic Resonance (EPR) spectra for the glasses doped of V2O5 (x≤3 mol %) has been recorded on the x-band ( = 9.14GHz) at room temperature. The spin Hamiltonian parameters, dipolar hyperfine coupling parameter, P and Fermi contact interaction parameter, K have been calculated. It has been found that V4+ions in these glasses exist as V2+ in octahedral coordination with a tetragonal distortion. Optical absorption spectra for the prepared glasses have been measured by UV-VIS spectrophotometer in the wavelength range (190-1200 nm) at room temperature. The optical energy gap values have been calculated and show indirect transition mechanism. The optical energy gap values E.g. have been calculated and were found to decreases with doping of V2O5. Also Urbach energy gap ∆E values have been estimated and were found to increases with doping of V2O5.