OPTICAL AND SPECTROSCOPIC STUDIES OF Fe2O3-Bi2O3-B2O3:V2O5 GLASSES

The glasses of compositions xFe2O3⋅ (40 - x)Bi2O3⋅60B2O3⋅2V2O5 have been prepared by the standard melt-quenching technique. Amorphous nature of these samples is ascertained by XRD patterns. The presence of BO3 and BO4 units is identified by IR spectra of glass samples. The absorption edge (λcut-off) shifts toward longer wavelengths with an increase in Fe2O3 content in the glass matrix. The values of optical band gap energy for indirect allowed and forbidden transitions have been determined and it is found to decrease with increase in transition metal ions. The Urbach's energy is used to characterize the degree of disorder in amorphous solids.