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

Abstract

© 2016 Elsevier B.V. All rights reserved. Glasses with compositions (100-x) Li2B4O7-x Nb2O5doped 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,NbO4and NbO6. From the intensities of some optical absorption bands, Judd-Ofelt parameters hΩλ(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.