Optical and electron paramagnetic resonance studies of VO2+ doped mixed alkali–alkaline earth oxide borate glass system
-
Published:2022
Issue:2
Volume:63
Page:43-49
-
ISSN:1753-3562
-
Container-title:Physics and Chemistry of Glasses: European Journal of Glass Science and Technology Part B
-
language:
-
Short-container-title:Phys. Chem. Glasses: Eur. J. Glass Sci. Technol. B
Author:
Srinivas G., ,Shiva Kumar J.,Shareefuddin Md.,Chary M. N.,Sayanna R.
Abstract
Glasses with the composition xK2O–(25−x) Li2O–12·5BaO–12·5MgO–48B2O3–2V2O5 (0≤x≤20) were prepared by the melt quenching method. The mixed alkali effect (MAE) has been investigated in the glass system through density, molar volume, optical absorption and EPR studies. VO2+ ions were used as the spin probes. From the optical absorption studies the values of the optical band gap (Eopt) for indirect transitions and the Urbarch energy (∆E) were evaluated. The values of Eopt, ∆E and density exhibited nonlinear behaviour with the variation of Li2O content, which may be attributed to the mixed alkali effect. The EPR spectra have structures which are characteristic of a hyperfine interaction arising from an unpaired electron with the 51V nucleus and it builds up in intensity as x increases. The spin-Hamiltonian parameters were evaluated from the EPR spectra. For x=0 mol%, the EPR spectrum was found to be more intense and well resolved. The variation of g‖ versus A‖ and N versus 1/x as a function of Li2O content was found to be nonlinear, which may be due to the mixed alkali effect. The results obtained were explained.
Publisher
Society of Glass Technology
Subject
Materials Chemistry,Physical and Theoretical Chemistry,Condensed Matter Physics,Electronic, Optical and Magnetic Materials