Investigation of optical properties of glasses with composition of ( P2O5 – V2O5 – Li2O – Na2O )

Glassy samples with a composition of 40P2O5–10V2O5–(50-x)Li2O– xNa2O, were prepared by the conventional melt quenching technique in two forms of bulk and blown film. To confirm the amorphous nature of the samples, x-ray diffraction (XRD) analysis was accomplished .The optical absorption spectra of the blown glassy films, were recorded with an UV-Vis spectrophotometer. X-ray diffraction patterns corroborated the amorphous feature of the samples. From the absorption edge studies, the values of optical band gap and Urbach energy, have been evaluated.The values of optical band gap and Urbach energy,vary non-linearly with concentration of x, which confirmed the existence of mixed alkali effect ( ΜΑΕ).