The role of dysprosium ions on the physical and optical properties of lithium-borosulfophosphate glasses

Abstract

Achieving outstanding physical and optical properties of borosulfophosphate glasses via controlled doping of rare earth ions is the key issue in the fabrication of new and highly-efficient glass material for diverse optical applications. Thus, the effect of replacing P2O5 by Dy2O3 on the physical and optical properties of Dy3+-doped lithium-borosulfophosphate glasses with chemical composition of 15Li2O-30B2O3-15SO3-(40 - x)P2O5-xDy2O3 (where 0.0 mol.% ≤ x ≪ 1.0 mol.%) has been investigated. The glass samples were synthesized from high-purity raw materials via convectional melt-quenching technique and characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectrometry (EDX), density and UV-vis-NIR absorption measurements. The amorphous nature of the prepared glass samples was confirmed by XRD patterns whereas the EDX spectrum depicts elemental traces of O, C, B, S, P and Dy. The physical parameters such as density, refractive index, molar volume, polaron radius and field strength were found to vary nonlinearly with increasing Dy2O3 concentration. UV-vis-NIR absorption spectra revealed seven absorption bands with most dominant peak at 1269 nm (6H15/2 →6F11/2 +6H9/2). From the optical absorption spectra, the optical bandgap and Urbach's energy have been determined and are related with the structural changes occurring in these glasses with increase in Dy2O3 content. Meanwhile, the bonding parameters (δ) evaluated from the optical absorption spectra were found to be ionic in nature. The superior features exhibited by the current glasses nominate them as potential candidate for nonlinear optical applications.