Study of electron paramagnetic resonance in vanadyl doped tungsten lithium borate glasses

Glasses with composition xWO 3 .(30-x)Li 2 O.70B 2 O 3 containing 2 mol % V 2 O 5 have been prepared over the range 0≤ x≤ 15 (x is in mol % and in steps of 2.5). The electron paramagnetic resonance (EPR) spectra of VO 2+ in these glasses have been recorded on X-band (ν ≈ 9.14 GHz) at room temperature (RT). The spin Hamiltonian parameters, dipolar hyperfine coupling parameter, P and Fermi contact interaction parameter, K, have been calculated. It has been found that V 4+ ions in these glasses exist as VO 2+ in octahedral coordination with a tetragonal distortion. Results suggest that the tetragonality of the V 4+ O 6 complex changes with change in WO 3 :Li 2 O ratio. Values of theoretical optical basicity have also been calculated.