Optical and Structural Evaluation of Lithium Strontium Borate Glasses Doped with Copper Ions

摘要

Background: The alkali borate glasses containing transition metal ions are ofgreat interest for opto-electronic applications. However, there is no systematic study on thelithium strontium borate glasses doped with CuO.Objectives: The aim of this study is to present a complete structural and optical view ofthis glass system and the influence of CuO content on these parameters.Methods: Li2O-SrO-B2O3 glasses containing different concentrations of CuO wereprepared using the melt quenching technique. The prepared glasses have been investigatedby measuring physical properties like density and molar volume, structural properties usingFTIR spectroscopy and Raman spectroscopy, optical properties using UV-Visspectroscopy and the compositional effects on spin-Hamiltonian parameters using EPRspectroscopy.Results: The X-ray diffraction patterns of all the studied samples revealed the amorphousnature. The density, molar volume and refractive index, optical band gap energy andUrbach energy vary with the concentration of CuO. The IR and Raman spectroscopicstudies revealed that copper ions lead to structural rearrangements through the conversionof three-coordinated boron into four-coordinated boron and thereby reducing the numberof non-bridging oxygen atoms. The electron paramagnetic resonance spectra of all thestudied glasses exhibit resonance signals characteristic of Cu2+ ions. The values of spin-Hamiltonian parameters indicate that the Cu2+ ions are present in the distorted octahedralsites.Conclusion: The analysis of these results indicated that majority of the copper ions exist inCu2+ state in these glasses up to 0.8 mol% of CuO and above this concentration some ofthese ions may convert into Cu+ state. The dependency of various physical, structural andoptical properties on the concentration of copper ions shows good application prospectiveof this glass system for different applications.