INVESTIGATIONS OF ELECTRON-PARAMAGNETIC-RESONANCE PARAMETERS OF OCTAHEDRAL (CrO₆)^9- and (MnO₆)^8- CLUSTER IN MgTiO₃:Cr³⁺, SrTiO₃:Cr³⁺ AND SrTiO₃:Mn⁴⁺ CRYSTALS

Abstract

The complete high-order perturbation formulas are established by both crystal-field (CF) and charge-transfer (CT) mechanisms. The EPR g factors of MgTiO 3 : Cr 3+ , SrTiO 3 : Cr 3+ and SrTiO 3 : Mn 4+ crystals are calculated from the formulas. The calculations of the EPR g factors are in agreement with the experimental values. The contribution rate of the CT mechanism (|Δg T /Δg F |) to EPR parameters, increases with the growth of the valence state for the 3d n ions in the crystals. For the higher valence state 3d 3 ion Mn 4+ in crystals, the explanation of the EPR parameters reasonably involves both CF and CT mechanisms. The g values are also given from one-spin-orbit-parameter model and crystal-field (CF) mechanism for comparison.