Spectral investigations on VO 2+ ion doped in CaO–SrO–Na 2O–B 2O 3 glass systems

Abstract

Glasses of the (20 − x)CaO–xSrO–(20 − y)Na 2O–60B 2O 3 − y (CSNB) system with (5 ≤ x ≤ 15) mol% and y = 0.1 mol% of V 2O 5 were characterized by X-ray diffraction (XRD), EPR (Electron Paramagnetic Resonance), Optical absorption Spectra and FT-IR (Fourier transform Infrared Spectroscopy) studies. EPR spectra of all the glass samples exhibit resonance signals characterstic of VO 2+ ions. The values of spin-Hamiltonian parameters indicate that the VO 2+ ions in CSNB glasses were present in octahedral sites with tetragonal compression and belong to C 4v symmetry. Spin-Hamiltonian parameters ‘g’ and ‘A’ were evaluated. The Optical band energy (E opt) and Urbach energy (ΔE) were calculated from their ultra violet edges. By correlating EPR and Optical data the molecular orbital coefficients have been evaluated. IR spectra of these glasses were analyzed in order to identify the contribution of each component to the local structure that determines the physical properties of these glasses.