Electron Spin Resonance of V4+ Ions in K2O-B2O3-V2O5 Glasses

Abstract

In the present work the ESR study of potassium borovanadate (K2O-B2O3-V2O5) glasses is reported at room temperature and liquid nitrogen temperature. The spectra at liquid nitrogen temperature is similar to at room temperature except the indusial hyperfine lines are sharper and more intense which might be ascribed to a spin-lattice relaxation effect. The ESR parameters were calculated at room temperature and shows that in-plane π bonding is somewhat covalent and covalency is nearly independent of concentration of K2O. The octahedral site with a tetragonal compression gives g value in the order g׀׀< g< ge(=2.0023). It is observed that the V4+ ions in the present sample exist as VO2+ ions in octahedral coordination with a tetragonal compression and belong to C4v symmetry.