ELECTRON-SPIN-RESONANCE OF V(4+) CENTERS IN V-TI COMPLEX OXIDE POWDERS

The ESR spectra of paramagnetic species in the bulk of a VxTi1-xO2 anatase preparation (g⊥ = 1.957; g∥ = 1.924; |a⊥| = 54 G; |a∥| = 165 G) and in the bulk (g⊥ = 1.962; g∥ = 1.958; |a⊥| = 50 G; |a∥| = 150 G) and on the surface (g⊥ = 1.971; g∥ = 1.905; |a⊥| = 72 G; a = 72 G; |a∥| = 190 G) of a poorly crystalline rutile V2O5-TiO2 preparation have been recorded and simulated by a computer program. The spectral parameters derived from the simulated spectra are compared with those reported in the literature for several vanadia-titania mixed oxides having different structures and compositions, and of known V(4+) complexes. The coordination sphere of V(4+) in these materials is discussed. © 1990.