Effect of CuO on physical, structural and optical properties of lithium borosilicate glasses

This paper reports the effect of copper on the physical, structural and optical properties of lithium borosilicate glasses with the composition of 50B2O3-30SiO2-(20-x) Li2O-xCuO (x = 2, 4, 6, 8, 10 mol %) synthesized by the conventional melt-quench technique. The prepared samples were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and UV-visible spectroscopy to study their structural and optical properties. Various physical parameters such as density, molar volume, oxygen packing density, ionic concentration and their inter-ionic distance are investigated. The band gap decreases from 3.64 to 2.70 eV with CuO doping into Li2O. The BO4 structural units change into BO3 units with the addition of CuO. The change in dielectric constant, extinction coefficient, refractive index and skin depth as a function of wavelength is also discussed. The theoretical optical basicity and oxide ion polarizability are found to increase with Li2O doping in place of CuO.