ELECTRON-PARAMAGNETIC RESONANCE AND OPTICAL-ABSORPTION SPECTRA OF VO2+ IONS IN ALKALI CADMIUM BOROSULFATE GLASSES

The electron paramagnetic resonance spectrum at 9.205 GHz has been examined at 300 K for a series of VO2+ ion doped R2SO4-B2O3-CdSO4 (R = Li, Na, K, or Cs) glasses and the spin Hamiltonian parameters, dipolar hyperfine coupling parameter, P, and Fermi contact interaction parameter, K, have been evaluated from the spectra. It was found that these parameters are independent of the alkali ion in the glass. The theoretical value of optical basicity (AND th) of glasses has also been calculated. The values of the spin Hamiltonian parameters indicate that V4+ ions are present in the glasses as VO2+ in an octahedral site with a tetragonal compression. The optical absorption spectra of VO2+ ions in glasses show two bands. By correlating the electron paramagnetic resonance and optical data, the molecular orbital coefficients have been evaluated.