Investigations of the Defect Structures and g Factors for SnO2:Cr5+, SnO2:V4+, and TiO2:V4+ Crystals

The electron paramagnetic resonance (EPR) g factor formulas for SnO 2 :Cr 5+ , SnO 2 :V 4+ and TiO 2 :V 4+ crystals are deduced from Jahn–Teller effect and contributions of the charge-transfer levels. The tetragonal distortions Δ R = −0.0283, −0.0091, and −0.0045 nm, and Δ θ = 0°, −0.0335°, and −0.0010°, for SnO 2 :Cr 5+ , SnO 2 :V 4+ and TiO 2 :V 4+ , respectively. The calculations of the g factors agree well with the experimental values. The contributions of the charge-transfer levels to g factors increase with the increasing valence state. It must be taken into account in the precise calculations of g factors for the high-valence state d 1 ions in crystals.