Structural, optical and dielectric characterization of niobium lithium tetraborate glasses doped praseodymium

• Niobium lithium tetraborate glasses doped praseodymium was synthesized.
• JO theory is implemented for the analysis of optical absorption spectra Pr3 + ion.
• Structure and some properties of present samples modified with Nb2O5 were studied.

Glasses with compositions (100-x) Li2B4O7-x Nb2O5 doped 1 mol% Pr6O11 (where x = 15, 25 and 35 mol%) were prepared. The glass nature of the present samples was established by X-ray diffraction (XRD) which is confirmed by differential thermal analysis (DTA) study. The infrared absorption spectra indicate that the structural units of the present samples are made up of BO3, BO4, NbO4 and NbO6. From the intensities of some optical absorption bands, Judd-Ofelt parameters Ωλ (λ = 2, 4, 6) have been evaluated. The variations in some physical properties such as the density (ρ), molar volume (VM), optical band gap (Eg) and Urbach energy (E0) have correlated with structural changes in the glass samples. Measurements of the dielectric constant, dielectric loss and ac conductivity as a function of frequency (120 Hz − 100 kHz) and temperature (310–670 K) have also reported.